Automated telescope with distributed orientation and operation processing

ABSTRACT

A fully automated telescope system is able to be fully operable in both Alt-Az and polar configurations. In either configuration, the telescope aligns itself to the celestial coordinate system following a simplified initialization procedure during which the telescope tube is first pointed north and then pointed towards a user&#39;s horizon. A command processor, under application software program control orients the telescope system with respect to the celestial coordinate system given the initial directional inputs. The initial telescope orientation may be further refined by initially inputting a geographical location indicia, or by shooting one or two additional celestial objects. Once the telescope&#39;s orientation with respect to the celestial coordinate system is established, the telescope system will automatically move to and track any desired celestial object without further alignment invention by a user.

PRIORITY CLAIM

[0001] This application takes priority from provisional patentApplications Serial Nos. 60/105,626, filed Oct. 26, 1998 entitled “FULLYAUTOMATED TELESCOPE SYSTEM WITH DISTRIBUTED INTELLIGENCE” and60/143,637, filed Jul. 14, 1999, entitled “SELF ORIENTING, SELFALIGNING, INTUITIVE AUTOMATED TELESCOPE”, the entire contents of whichare expressly incorporated herein by reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present application is related to co-pending applicationentitled UPGRADEABLE TELESCOPE SYSTEM and co-pending applicationentitled INTELLIGENT MOTOR MODULE FOR TELESCOPE AXIAL ROTATION, commonlyowned by the assignee of the present invention, the entire disclosuresof which are expressly incorporated herein by reference.

FIELD OF THE INVENTION

[0003] The present invention relates to telescopes or other observationinstruments and, more particularly, it relates to fully automatedtelescope systems with distributed intelligence and control systems forsuch telescopes.

SUMMARY OF THE INVENTION

[0004] The present invention relates to fully automatic telescopesystems which are capable of performing alignment and orientationoperations under program control with a minimum of intervention by auser. The telescope system is able to perform its alignment andorientation functions regardless of whether it might be configured as analt-azimuth telescope or as an equitorial telescope. In accordance withthe invention, the system is provided with sufficient processing powerand with a multiplicity of application routines so that, alignment andorientation is performed with regard to a large number of differentalgorithms and with respect to a variety of user definable data typeinputs. All that is required is that some location index be provided tothe system and that the system's motors are initialized to a horizontaland vertical referant. Time might be included as an input parameter,whether user provided, or by automatic extraction from a peripherallycoupled device. Location indices as well as horizontal and verticalreferants might be user provided, obtained under user direction, orautomatically obtained from various other peripherally coupled devices.

[0005] The telescope system has a distributed intelligence in that itsmotor control functions are independently developed by motor modulesincluding a microcontroller, operating on motor movement commandsreceived from a hand held command module, in combination with positionfeedback information derived from optical encoders coupled to each motorshaft. Alternatively, the encoders might be coupled to each of atelescope's two generally orthogonal axes, and encoder feedback signalsdirected to the motor module microcontrollers.

[0006] Distributed intelligence is further characterized in that thetelescope system hand held command module might be provided in twoseparate configurations. A first configuration is simplified, and onlyprovides direction and speed commands to the intelligent motor modules.System intelligence thus resides in the motor modules with the commandmodule functioning more as a steering wheel, or directional joy stick.

[0007] In a second configuration, the command module is a fullyfunctional microprocessor controlled command unit, capable of executinghigh level application software routines and performing numerous dataprocessing tasks, such as numerical calculations, coordinate systemtransformations, database manipulations, and managing the functionalperformance of various different peripherally coupled devices.

[0008] A central interface panel is provided on the telescope system andsupports interconnection between and among the intelligent motormodules, the command module (of either form) and peripheral devices.Communication between and among the component parts is made over serialdata and control communication channels in accordance with a packetbased serial communication protocol. An RS-232 port is also providedsuch that a command module is able to communicate with ancillary RS-232capable devices like personal computer systems and/or a command modulebelonging to another intelligent telescope system according to theinvention.

[0009] Use of the various communication channels allows the telescopesystem according to the invention to communicate with other devices inorder to exchange stored information, exchange created and storedoperating routines, obtain updates to programs and/or internal databasesand the like. In this regard, the telescope system includes a number ofinternal databases, including at least one database of the celestialcoordinates (RA and DEC) of known celestial objects that might be ofinterest to an observer. Further, the system includes a database of thegeographical coordinates (Latitude and Longitude) of a large body ofgeographical landmarks. These landmarks might include the knowncoordinates of cities and towns, cartographic features such asmountains, and might include the coordinates of any definable point onthe earth's surface whose position is stable and geographicallydeterminable. Each of the databases are user accessible such thatadditional entries, of particular interest to a user, might be included.

[0010] The solution to any given problem in celestial trigonometrydepends on being able to convert measurements of obtained in onecoordinate system (alt-az, for example) into a second coordinate system(the celestial coordinate system). The present invention relates to asystem and method for orienting a computerized telescope system of thetype including a telescope coupled for rotation about two orthogonalaxes, with respect to a spherical coordinate system. The telescope isprovided with a pair of motors, each motor coupled to rotate thetelescope about a respective one of the orthogonal axes. Each motorfurther includes a positional reference indicator which defines anarcuate position of the telescope with respect to its correspondingaxis. Positional reference information is taken from each positionalreference indicator and provided to a control processor which isprogrammed to carry out the calculations necessary for effectingcoordinate system transformation.

[0011] In a first line of procedure, the computerized telescope systemis able to locate its own alignment stars based on date and time entriesprovided by a user during an initialization procedure. Specifically, thetelescope is moved about one of its orthogonal axes until the telescopeis pointed at a first positional reference. In one aspect of theinvention, the first positional reference is North.

[0012] After the telescope system is pointed to the first positionalreference, the arcuate position of that positional reference indicatoris recorded and stored by the control processor so as to define a firstreference position. Next, the telescope is moved about a second axis inorder to position the telescope at a second reference point. In aparticular aspect of the invention, the second reference point is thehorizon, thus causing the telescope to be leveled. The arcuate positionof the respective positional reference indicator is read and recorded tothereby define a second reference point.

[0013] Particularly, the positional reference indicators are positionencoders of altitude and azimuth motor assemblies. Pointing thetelescope North and leveling the telescope, functions to zero-in theposition encoders of the altitude and azimuth motor assemblies. Anysubsequent motion of the telescope away from its 0,0 position allows thetelescope system to directly calculate its altitude and azimuthdisplacements from the 0,0 reference point.

[0014] Using time and date entries provided by a user, the telescopesystem consults a database of well known celestial objects and selects aparticular bright object which is currently above the horizon. Theentered time and date information allows the system to calculate whetherthat particular bright object has rotated sufficiently in rightascension to bring it above the observer's horizon, while a virtuallatitude and longitude entry provided by an observer's entering ageographical indicia, provides the system with sufficient informationregarding an observer's latitude such that it may calculate adeclination value for the desired viewing object.

[0015] The system automatically slews the telescope to the vicinity ofthe desired viewing object by commanding the appropriate motion from thealtitude and azimuth motors. Once the telescope has slewed to thevicinity of the desired star, the observer is prompted to center thestar in the field of view of the telescope eyepiece. Once the star iscentered in the field of view of the eyepiece, the system calculates theposition and orientation of the telescope with respect to the night sky(the celestial sphere).

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] These and other features, aspects and advantages of the presentinvention will be more fully understood when considered with respect tothe following detailed description, appended claims and accompanyingdrawings wherein:

[0017]FIG. 1 is a semi-schematic perspective view of one embodiment of atelescope system in accordance with the present invention, configured inan initial, un-automated manner;

[0018]FIG. 2 is a semi-schematic perspective view of the telescopesystem of FIG. 1, including semi-intelligent drive motors coupled to thetelescope axes and illustrating alternative control systems.

[0019]FIG. 3a is a semi-schematic partial perspective view of anelectrical interface panel in accordance with the present invention;

[0020]FIG. 3b is a semi-schematic block diagram of the signal and busconfiguration of the electrical interface panel of FIG. 3a;

[0021]FIG. 4a is a semi-schematic exploded perspective view of asemi-intelligent motor assembly in accordance with the presentinvention;

[0022]FIG. 4b is a semi-schematic block diagram of the electricalcomponents of a semi-intelligent motor assembly in accordance with thepresent invention;

[0023]FIG. 5a is a semi-schematic front view of an embodiment of asemi-intelligent dual-axis drive motor motion control system accordingto practice of principles of the present invention;

[0024]FIG. 5b is a semi-schematic block diagram of the electroniccomponents of the embodiment of the semi-intelligent dual-axis drivemotor motion control system of FIG. 5a;

[0025]FIG. 6a is a semi-schematic front view of an intelligent dual-axisdrive motor motion control system according to practice of principles ofthe present invention;

[0026]FIG. 6b is a semi-schematic block diagram of the electroniccomponents of the embodiment of the intelligent dual-axis drive motormotion control system of FIG. 6a;

[0027]FIG. 7a is a simplified waveform diagram of ideal photodetectoroutput characteristics, illustrating a quadrature output pattern;

[0028]FIG. 7b is a simplified waveform diagram illustratingphotodetector “on” and “off” periods in accord with the invention;

[0029]FIG. 7c is a simplified waveform diagram depicting dynamicallytuned photodetector output characteristics, exhibiting an idealquadrature output pattern;

[0030]FIG. 8 is a conceptual flow diagram of an initialization procedurein accordance with the invention;

[0031]FIG. 9 is a database table illustrating an exemplary locationentry;

[0032]FIG. 10a is a conceptual flow diagram of a first, “easy” alt-azalignment and orientation procedure in accord with the invention;

[0033]FIG. 10b is a conceptual flow diagram of a second, single star,alt-az alignment and orientation procedure in accord with the invention;

[0034]FIG. 10c is a conceptual flow diagram of a third, two-star, alt-azalignment and orientation procedure in accord with the invention;

[0035]FIG. 11a is a conceptual flow diagram of a first, “easy” polaralignment and orientation procedure in accord with the invention;

[0036]FIG. 11b is a conceptual flow diagram of a second, single star,polar alignment and orientation procedure in accord with the invention;

[0037]FIG. 11c is a conceptual flow diagram of a third, two-star, polaralignment and orientation procedure in accord with the invention;

[0038]FIG. 12 is an exemplary line listing of a communication packet inaccordance with the interface protocol of the invention;

[0039]FIG. 13 is a simplified partial perspective view of a uniformillumination lightbox;

[0040]FIG. 14 is a perspective view of a second embodiment of atelescope according to the invention, having integrated motorassemblies;

[0041]FIG. 15 is a simplified, exploded, partial perspective view of adeclination (altitude) motor assembly integrated into a fork arm of thetelescope of FIG. 14;

[0042]FIG. 16 is a simplified, partial perspective view of a rightascension (azimuth) motor assembly integrated into the base housing ofthe telescope of FIG. 14;

[0043]FIG. 17 is a simplified schematic diagram of an MR sensor usefulin practice of the present invention;

DETAILED DESCRIPTION

[0044] The detailed descriptions of a fully automated telescope systemwith distributed intelligence set forth below in connection with theappended drawings are intended only as a description of the presentlypreferred and illustrated embodiments of the invention, and are notintended to represent the only form in which the present invention maybe constructed or utilized. The detailed descriptions set forth theconstruction and function of the invention as well as the sequence ofsteps utilized in the operation of the invention in connection with theillustrated embodiments. It is to be understood by those having skill inthe art, that the same or equivalent of functionality may beaccomplished by various modifications to the illustrated embodimentswithout departing from the spirit and scope of the invention.

[0045] A fully automatic telescope system with distributed intelligenceand a control system for operating such a telescope will now bedescribed with reference to the embodiments illustrated in the Figures.

[0046] In FIG. 1, a telescope system 10 for observing celestial, andterrestrial, objects is provided in accordance with the presentinvention. The telescope system 10 suitably comprises a telescope tube12 which houses the optical system required for resolving distantobjects and including a focusing objective and eyepiece 14 coupled tothe optical system in a manner to allow observation of the opticalsystem's focal plane. The telescope tube 12 is supported by a mount 16which facilitates movement to the telescope tube 12 about two orthogonalaxes, a substantially vertical axis, termed an azimuth axis and asubstantially horizontal axis, termed an altitude axis. As those havingskill in the art will appreciate, the horizontal and vertical axes ofthe mount 16 in combination define a gimbaled support for the telescopetube 12 enabling it to pivot in a horizontal plane defined by thevertical (or azimuth) axis and, independently, to pivot through avertical plane defined by the horizontal (altitude) axis.

[0047] It should be noted, at this point, that the telescope system 10is illustrated as comprising a telescope tube 12 configured as arefracting-type telescope. However, the form of the telescope's opticalsystem, per se, is not particularly relevant to practice of principlesof the present invention. Thus, even though depicted as a refractor, thetelescope system 10 of the present invention is eminently suitable foruse with reflector-type telescopes. The specific optical systems usedmight be Newtonian, Schmidt-Cassegrain, Maksutov-Cassegrain, and anyother conventional reflecting or refracting optical system configuredfor telescopic use.

[0048] In the telescope system embodiment illustrated in FIG. 1, it isconvenient to support the telescope tube and mount combination in such amanner that the vertical axis 18 is, indeed, substantially vertical suchthat the telescope pivots (or rotates) about the vertical axis in aplane which is substantially horizontal. A tripod, indicated generallyat 22, conventionally functions to support the mount 16 such that theazimuth axis 18 is substantially orthogonal to a horizontal plane,relative to a user of a telescope system. The tripod 22 includes threelegs 24 a, b, c, which are arranged in a triangular pattern. Each of thelegs are independently adjustable for leveling the mount 16 regardlessof the nature of the surface on which the telescope system 10 is used.

[0049] The illustrated embodiment of the telescope system of FIG. 1 is amanual, non-automatic embodiment in that the telescope tube 12 ispivotally moved about the azimuth axis 18 and altitude axis 20 by auser's grasping and manually moving an axially mounted azimuth controlknob 26 and an axially mounted altitude control knob 28. Each of thecontrol knobs 26 and 28 are journaled to respective axis pins through aconventional gearing system such that small and precise movements of thetelescope tube 12 may be made about the azimuth and altitude axes 18 and20 by relatively large rotations of the control knobs 26 and 28. In thisrespect, the telescope system 10 of FIG. 1 resembles a conventional,manually operated telescope system.

[0050] In addition to supporting telescope motion about two orthogonalaxes, the mount 16 further comprises an electrical interface junctionpanel 30 which, in a manner to be described in greater detail below, isconfigured to support upgradeability of the telescope system 10 into afully automatic telescope system with distributed intelligence, in aplurality of logically consistent steps, each of which results in afully functional telescope system having greater or lessor degrees ofintelligence and functionality, depending on where, along the upgradespectrum, user achieves the most subjectively desirable ratio betweensystem complexity and functional benefit.

[0051] Turning now to FIG. 2, there is depicted a semi-schematicperspective view of the telescope system 10 of FIG. 1, includingsemi-intelligent motor means for pivotally moving telescope about theazimuth axis 18 and altitude axis 20. Semi-intelligent motor meanssuitably comprises a semi-intelligent, self-contained azimuth axis drivemotor assembly 32 and a semi-intelligent, self-contained altitude axisdrive motor assembly 34. Each of the drive motor assemblies 32 and 34are self-contained motor packages including a DC brush-type motor, anassociated electronics package hosted on a printed circuit board, areduction gear assembly and an optical encoder assembly, configuredtogether in a housing in a manner according to co-pending patentapplication entitled INTELLIGENT MOTOR MODULE FOR TELESCOPE AXIALROTATION, filed on instant date herewith and commonly owned by theAssignee of the present invention, the entire disclosure of which isexpressly incorporated herein by reference. The semi-intelligent motorassemblies 32 and 34 are each affixed to the telescope mount 16 andcoupled to the azimuth and altitude axes 18 and 20, respectively, so asto be able to pivotally move the telescope tube 12 about thecorresponding axis when the motor assembly is activated. Each of themotor assemblies 32 and 34 are plugged into respective correspondingreceptacles in the electrical interface junction panel 30 which, in amanner to be described in greater detail below, functions as a signalinterface for the motor assemblies as well as providing power and groundthereto. The electrical interface junction panel 30 allows motor controlsignals to be directed to each of the motor assemblies 32 and 34, themotor control signals providing speed and direction information to theelectronics package which, in turn, provides appropriate activationsignals to the respective DC motor comprising the assembly. Theelectrical interface junction panel 30 further allows for signalcommunication between each respective one of the motor assemblies 32 and34 and a hand-held system control unit 36.

[0052] In operation, a user plugs the hand-held system control unit 36into an appropriate receptacle of the electrical interface junctionpanel 30 and further plugs the motor assemblies 32 and 34 into theirrespective receptacles, thus completing a signal path between each ofmotor assemblies and the system control unit 36. Motion commands areprovided to the system by the user by accessing the appropriate functionprovided on the system control unit 36. Signals corresponding to thedesired motion are directed by the control unit 36 to the appropriatemotor assembly through the electrical interface junction panel 30. Forexample, if a user desires to slew the telescope in a counter-clockwisedirection, he may enter a command into the control unit 36 telling thetelescope system to move “left”. In response, the azimuth axis motorassembly 32 is commanded to activate its integral motor to rotate in aparticular direction, thus causing the telescope mount to pivot in acounter-clockwise fashion about the azimuth axis 18. In like manner,when a user desires to elevate the telescope tube 12 in an upwardlydirection, the user would enter the appropriate “up” command into thecontrol unit 36, thus activating the altitude motor assembly 34, which,in turn, causes the telescope to pivot upwardly about the altitude axis20.

[0053] Turning briefly now to FIGS. 3a and 3 b, the mechanical andelectrical configuration of the electrical interface junction panel 30are illustrated. As can be understood from FIG. 3a, the interfacejunction panel 30 suitably comprises four RJ11-type connectorreceptacles, with three of the receptacles 38, 40 and 42, comprising4-pin RJ11 connectors and one of the receptacles 44, comprising an 8-pinRJ11 connector. In addition to the RJ11 connections, the electricalinterface junction panel includes a “mini pin” type 12 volt powerreceptacle 46 and a visible “power present” indicator comprising an LED48 mounted to shine through a recessed opening in the panel locatedproximate to the power pin 46.

[0054]FIG. 3b illustrates the electrical connections made between andamong the 4-pin RJ11 connectors, the 8-pin RJ11 connector and the 12volt power pin 46. External power is supplied to the various connectorscomprising the electrical interface panel 30 by a suitable 12 volt powersource 48 which might comprise a dedicated 12 volt battery pack or,alternatively, an adaptor configured to mate with a 12 volt automotivebattery through, for example, an accessory power plug or a cigarettelighter. The external power source 48 is plugged into the 12 volt powerpin 46 which takes the 12 volt potential from the pin's center post anddistributes it to pin 1 of the 8-pin RJ11 connector 44 and the No. 4 pinof each of the 4-pin RJ11 connectors 38, 40 and 42. The 12 voltpotential is referenced to a return or ground potential, contacting asleeve surrounding the center post, in conventional fashion, and thereference potential is directed to the No. 8 pin of the 8-pin RJ11connector 44 and the No. 1 pin of the 4-pin RJ11 connectors 38, 40 and42. In addition, the 12 volt supply is dropped across aseries-configured resistor 50 and LED diode 48 combination such that theLED 48 emits when a power supply is present. Thus, a user is able todetermine if the system is powered-up by examining the LED 48 disposedin the recessed opening 48 in the electrical interface junction panel.

[0055] In addition to power and ground, each of the 4-pin RJ11connectors 38, 40 and 42 further comprise a 2-conductor serial signalpath with pin No. 3 of each of the connectors identified to a serialsignal termed “CLK” and pin No. 2 of each of the connectors identifiedto a serial signal termed “DATA”. A first 4-pin RJ11 connector 38 isconfigured as a connector for supporting various pieces of auxiliaryequipment and its serial signal lines are each identified as “AUX”. TheCLK and DATA signals comprising pins 3 and 2, respectively, areidentified as AUX CLK and AUX DATA respectively. Likewise, the next4-pin RJ11 connector 40 is configured to provide serial CLK and DATAsignals to the altitude motor assembly 34 (alternatively a declinationmotor assembly) and its CLK and DATA signal lines are thus denoted ALTCLK (Dec CLK) and ALT DATA (Dec DATA) respectively. 4-pin RJ11 connector42 is configured to provide serial CLK and DATA signals to the azimuthmotor assembly 32 (alternatively a right ascension motor assembly) andits CLK and DATA signals are referred to respectively as AZ CLK (RA CLK)and AZ DATA (RA DATA).

[0056] Each of the respective CLK and DATA signals of each of therespective 4-pin RJ11 connectors are electrically connected to acorresponding CLK and DATA signal pin of the 8-pin RJ11 connector 44.Thus, the AZ CLK and AZ DATA signal pins of connector 42 are coupled topin 6 and 7, respectively of the 8-pin RJ11 connector. ALT CLK and ALTDATA are connected to pins 4 and 5, respectively, of connector 44 andAUX CLK and AUX DATA are connected, respectively, to pins 2 and 3 ofconnector 44. The source of each of these signals suitably comprises thehand-held control unit 36 which provides such signals over a flexible 8conductor cable terminating in a male 8-pin RJ11 connector suitable formating with the 8-pin connector 44 disposed on the electrical interfacejunction panel 30.

[0057] Thus, it will be understood, that the electrical interfacejunction panel 30 provides a means for routing power and control signalsbetween and among an external power source and a control unit, aplurality of separately provided motor assemblies and various optionalauxiliary pieces of electronic equipment, such as electronic focusers,electronic leveling means, a global positioning system receiver, and thelike, so long as the auxiliary electronic equipment is configured tocommunicate over a 2 conductor signal bus supporting clock and datasignals.

[0058] The interface panel 30 can be viewed as essential distributionaxis which enables interconnection between and among the variouscomponents of the automated telescope system through 2-conductor serialbus connections. Each 2-conductor serial bus carries packetized commandand data signals on one wire and clock signals on the other. Each serialbus is coupled between an intelligent or semi-intelligent signal source,such as a system control unit (36 of FIG. 2) and either an axial drivemotor assembly or an auxiliary apparatus. The 2-conductor serial cablingbetween and among the different components of the system is an importantfeature of the present invention, since it allows the components to beinterconnected using small, thin, flexible cabling which is adapted forserial communication using a packet protocol. Commands and data arepassed from device-to-device in “bite sized” packets which merely informthe receiving device of the commands which the device is to execute.Large, thick, byte-wide cabling, conventionally comprising a largenumber of conductors suitable for both address and data busrequirements, are no longer required in an intelligent telescope systemaccording to the invention. Each of the novel components are suitablysized and provided with a suitable degree of intelligence so as to bequickly and simply coupled together with flexible serial interfacecables in order to realize the benefits of the system as a whole.

[0059] It bears mentioning that the use of small, thin, flexible serialinterconnect cabling significantly reduces the inertial drag on a systemthat would normally be present when using conventional multipleconductor cabling. In addition, the use of small, thin, flexible cablesvastly reduces the spring tension that conventional motor and cablesystems would apply to a telescope mount.

[0060] Pertinent to practice of principles of the present invention isthe degree of intelligence which is provided to the motor assemblycomprising either the azimuth or altitude axis motor assemblies 32 and34 of FIG. 2. Referring now to FIGS. 4a and 4 b, the intelligence ofeither of the motor assemblies is implemented in electronic circuitry 50hosted on a printed circuit board which is disposed within the motorassembly housing along with at least a motor 52 and an optical encodersubsystem 54. The electronic circuitry 50 communicates with the outsideworld over a serial interface bus which is coupled to the circuitrythrough a 4-pin connector 56. The connector 56 is adapted to be cableconnected to a control source through either the altitude motor RJ11connector 40 or the azimuth motor RJ11 connector 42 as described inconnection with the interface panel 30 of FIGS. 3a and 3 b. Power andground is taken from pins 1 and 4, respectively, of the connector 56 androuted to a power supply distribution circuit 58 wherein battery poweris filtered and regulated to a nominal voltage level required by thecircuitry, before being distributed to the active components comprisingthe circuit package 50. Additionally, the raw battery voltage isfiltered and provided to motor driver circuitry 51 as well as to therespective motor 52. Power distribution circuit 58, thus is able toprovide both regulated low voltages appropriate for an electroniccircuit, and filtered high voltages suitable for motor applications. Itshould be understood that while 12 Volts is preferred as a batterysupply voltage, the battery need not be limited thereto. So long as themotor and its associated driver circuitry are capable of operating athigher voltage levels, voltages as high as 16-18 Volts might be used.

[0061] The CLK and DATA lines of the serial interface are connected torespective inputs of a microprocessor 60 which functionally controlsoperation of its associated motor 52 under firmware program control.Microprocessor 60 is suitably implemented as an 8-bit microprocessor orcontroller, exemplified by the PIC16C54 microprocessor, manufactured andsold by Microchip Technology, Inc., and functions to control bothdirection of motion and speed of motion of its respective motor 52 byevaluating specific motor motion commands against a feedback signalprovided by an optical encoder assembly 54.

[0062] Although the PIC16C54 is described as a microprocessor, it istechnically an 8-bit, fully static, EPROM/ROM-based CMOS microcontrolleremploying a RISC architecture with 33 single word/single cycleinstructions. The PIC16C54 uses a Harvard architecture in which programinstructions and data are accessed on separate buses, thus improvingbandwidth over traditional von Neumann architectures where programinstructions and data are fetched on the same bus. The PIC16C54comprises a 512×12 instruction EPROM/ROM memory for hosting anoperational program instruction set and a 25 byte general purpose SRAMregister file memory. Separating the program and data memory allowsinstructions to be sized differently than the 8-bit wide data byte.Instruction opcodes are 12-bits wide making it possible to have allinstructions be single word-type instructions.

[0063] Conventionally, the PIC16C54 comprises three I/O ports, a 4-bitI/O register, termed port A and identified as pins A0 through A3, an8-bit I/O register termed port B and identified as pins B0 through B7,and an 8-bit I/O general purpose register termed port C and identifiedas pins C0 through C7. All ports may be used for both input and outputoperation. Each of the I/O pins are tri-state, and can be programmedindividually as either an input or an output.

[0064] As depicted in FIG. 4b, serial CLK and DATA inputs are directedto the bit-0 (A0) and bit-1 (A1) pins of the microcontroller's A port,respectively. Further, the bit-2 (A2) and bit-3 (A3) pins of themicrocontroller 60 define the motor motion control outputs and aredirected to the motor driver circuit 51 and thence to the circuit'sassociated motor 52 in order to define the scope of motor movement andits direction. As will be described in greater detail below, the I/Opins B0-B7 of port B of the microcontroller 60 are programmed to receivefeedback signals provided by an optical encoder assembly 54 which areprocessed in accordance with an application firmware program in order todefine encoder and, thus motor position. Clock input and output pins(OSC1 and OSC2, respectively) are connected to a crystal oscillator 61,operating at four times the instruction cycle rate, or 20 MHz, and whichdefines the timing reference signals for the microcontroller 60.

[0065] Commands are provided in serial fashion to the data input A1 ofthe microcontroller 60 in accordance with a packet communicationprotocol, with each command packet comprising one or more bytes ofinformation and with each information byte being sequentially clockedinto the microprocessor 60, bit-by-bit, by a clock signal provided tothe microprocessor's CLK pin A0. As will be understood by those familiarwith the PIC16C45 I/O, data transmission is bi-directional, while clocksignals are commonly sourced by a bus master device, such as a controlunit, as will be described presently.

[0066] Exemplary commands that are received and processed by themicroprocessor 60 include motor motion commands, more properly termed“step rate” commands, by which the microcontroller is instructed howfast, in which direction, and to what extent to move its associatedmotor. Since each motor is feedback controlled, feedback information,corresponding to actual motor movement, is stored in an “error count”register, internal to the microcontroller 60, whence it is available andmay be read out to a follow-on processor for evaluation. Furthercommands that may be processed by the microcontroller 60 includecommands for writing error count data to the register and readingmicrocontroller status information, including motor PWM count and thechange in motor position since the last status read operation.

[0067] Other commands that are supported by the particularmicrocontroller 60 of the illustrated embodiment, include commandsrelated to various power saving features commonly implemented in modernintegrated circuits. In particular, a SLEEP command places themicrocontroller in a “sleep” mode that terminates when the interfaceclock signal is next driven low. When in “sleep” mode, the watchdogtimer, if enabled, will be cleared and the device's oscillator driverwill be turned off. The I/O ports maintain the status they were inbefore the SLEEP instruction was executed, i.e., driving high, drivinglow, or hi-impedance (tri-state).

[0068] Upon receipt of a motor motion (or step rate) command, indicatingthat the electronic circuitry 50 is to command motor movement,operational firmware in the microcontroller 60 causes appropriate PWMsignals to be provided to its corresponding motor driver circuitry andthence to the motor 52, at the appropriate pulse rate and duty cycle.The motor 52 moves in response to its motion command; the extent,direction and speed of which are evaluated by an optical encoder system54 which provides motor positional feedback information in a closed-loopfashion.

[0069] In conventional, or classical, closed-loop control systems usedin connection with automated telescope control, one or more positionfeedback sensors may be placed anywhere between the motor shaft and thetelescope focal plane. Once a position feedback sensor is calibratedsuch that its output can be converted to an apparent stellar position,the sensor will automatically correct, through this calibration, for anysystematic errors from the motor shaft up to the position feedbacksensor.

[0070] In the particular embodiment of the present invention, theoptical encoder assembly 54 comprises a disk 55 (best seen in FIG. 4a)about whose circumference a pattern of alternating transparent andopaque slots are disposed which, when rotated through the path of alight source and photodetector, are able to generate a series of pulses.The optical encoder disk is coupled to the shaft of a drive motor 52 ina manner as described in co-pending application entitled INTELLIGENTMOTOR MODULE FOR TELESCOPE AXIAL ROTATION, commonly owned by theAssignee of the present invention, the entire disclosure of which isexpressly incorporated herein by reference. Since the motor 52 iscoupled to its corresponding telescope axis by means of gears (cog andworm) there is no need to take drive train slippage into account aswould be the case when using belts or friction transfer clutches.Accordingly, the optical encoder disk is able to be coupled directly tothe motor shaft and still provide position information with sufficientaccuracy to enable precise acquisition and tracking of stellar objects.

[0071] The optical encoder wheel 55 is disposed with respect to themotor circuit's circuit board such that its alternating teeth (or slots)are rotated through the path of a light source developed by an LED diode62 and a pair of bipolar photodetector transistors 63 and 64. A pair ofphotodetector transistors is used in the illustrated embodiment of theinvention in order to resolve incremental motor shaft angulardisplacement in quadrature. Thus, it will be understood that the encodersystem according to the present invention is an incremental encodersystem, as opposed to an absolute encoder system wherein the opticalencoder disk patterns are defined by either binary or Gray codes.

[0072] Pulses, for each incremental resolved motor shaft angle step, arecounted by the microcontroller 60 and the total encoder count value,representing full motion of the telescope about the axis, is evaluatedagainst the movement extent command given to the corresponding motor.Accordingly, it can be seen that if a particular motor were commanded torotate the telescope through fifty one seconds of arc in a positive(upwardly) direction, the microcontroller 60 is able to evaluate theoptical encoder system 54 to determine that the motor did, indeed, moveprecisely that amount, no more and no less. If the measured motor motionwere inconsistent with the commanded motor motion, the microcontroller60 is able to calculate the direction and extend of a subsequent motorcommand to move the motor (and thus the telescope) to its desiredposition.

[0073] The operation of the encoder system 54 will now be described inconnection with the waveform diagrams of FIGS. 7a, 7 b and 7 c. Inaddition, it will be evident to those having skill in the art that theseparation distance between the circumferentially disposed teeth of theoptical encoder wheel 55 is mapped to the linear displacement distanceseparating the photodetector transistors 63 and 64, such that as theoptical encoder wheel is rotated before the photodetectors, eachrespective photodetector will define a periodic output signalrepresenting increasing and decreasing brightness of a light sourceemitted by the LED diode 62. It should be further noted that theperiodic signals are 90° out-of-phase so as to define a signal inquadrature.

[0074] The most desirable signal characteristics, albeit not realizablein the physical world, are depicted in the waveform diagram of FIG. 7a.The output signal from each of the photodetectors is illustrated as asquarewave with a 50% duty cycle, with the output signal fromphotodetector No. 2 being 90° behind the output signal fromphotodetector No. 1. Evaluating both of the output signals incombination, it will be evident that there are four separatecombinations values for the signals, with the four combinationsrepeating in time in a periodic fashion. The four possible combinationsof signal values are: on-off, on-on, off-on and off-off. Because thesignal combinations appear in a particular, predetermined pattern, thedirection of motion of the encoder wheel 55 and, thus, the motor, can bedetermined by evaluating the development of the patterns. For example,for a given on-off initial phase state, if the pattern transitions to anon-on phase state, the motor is moving in a forward direction. If theon-off phase state transitions to an off-off phase state, the motor ismoving in the opposite (presumably) backward, direction. Further, eachphase state transition defines what is termed herein a “tick” anddefines ¼ of the angular rotation required to rotate the encoder wheel55 from a first tooth to the next tooth (1 period).

[0075] The definition of “on” and “off” is predicated on a photodetectoroutput signal passing between two pre-set threshold voltages. As seen inFIG. 7b, each photodetector output signal defines a periodic waveform,which, in a manner to be described in greater detail below, is adjustedto oscillate within a particular voltage envelope. In accordance withpractice of the invention, each photodetector signal is defined to be inthe “on” state when its voltage excursion reaches and exceeds a 2.0 voltthreshold level. Each photodetector remains in the “on” state until itssignal level drops to a value of approximately 0.8 volts, whence thephotodetector output is deemed to switch from the “on” to the “off”state. The photodetector remains in the “off” state until its voltagevalue again reaches the 2.0 volt threshold level, whence it switches tothe “on” state. Accordingly, it can be seen that each of the signalsfrom the respective photodetectors define alternating “on” periods and“off” periods so as to define quadrature patterns.

[0076] In FIG. 7c, the periodic signals from the two photodetectors ofFIG. 7b, have been superposed, so as to define the quadrature pattern:on-off, on-on, off-on and off-off.

[0077] Returning to FIG. 4b, the photodetector transistor 63 and 64 arepreferably implemented as MPN transistors with their collector terminalsconnected in common to V_(cc) and their respective emitter terminalscoupled to I/O pins B0 and B1 of the microcontroller 60. Themicrocontroller is thus able to count each of the quadrature ticks andevaluate the quadrature pattern so as to determine both motor speed andmotor direction by evaluating each photodetector's output. As regardsmotor movement commands, the microcontroller 60 is configured to providePWM signals to the motor driver 51 which, in turn, supplies appropriatemotor rotation signals to its associated motor 52. The microcontroller60 outputs PWM signals (pulses) at a 150 pulse per second repetitionrate and determines actual motor speed by varying the duty cycle of eachpulse. For example, to run the motor at its maximum speed, the dutycycle for each pulse would be set to approximately 99%, i.e.,substantially always on, and the repetition rate set at the maximum 150pulses per second rep rate. In contrast, were the microcontroller 60commanded to run the motor 52 at a sidereal rate, the microcontroller 60would issue PWM pulses to the motor driver 51 having an approximately 2%duty cycle and at a substantially slower repetition rate. In thisregard, it should be noted that when running at the sidereal rate, thePWM pulse rate should equal or exceed approximately 45 pulses per secondin order that the resulting telescope motion not be apparently jerky tothe human eye. It has been established that step-wise motion atrepetition rates exceeding 45 repetitions per second appears smooth andcontinuous to the human eye. Thus, PWM pulse rates should meet or exceedthis 45 pulse per second repetition rate and the motor mechanicalgearing system adjusted accordingly. Given the maximum PWM pulse rate of150 pulses per second, it will be understood that the maximum pulserepetition rate defines a minimum time window between like pulsetransition edges of approximately 6 milliseconds. In order to determinemotor speed, the microcontroller 60 counts the number of “ticks” itreceives from the optical encoder system within the 6 millisecond timingwindow. The microcontroller evaluates the number of ticks received inthe window against the number of ticks expected and, if the number ofticks received is greater than or less than the number of ticksexpected, establishes an error count in an internal register. Themicrocontroller then adjusts the motor pulse duty cycle in order toslow-down or speed-up the motor in response to the magnitude and sign ofthe error count. The resulting ticks are again compared to a nominalestablished value, with excess ticks being added to the error countregister and the shortfall being subtracted therefrom. The processcontinues until the error register is substantially zeroed-out, meaningthat the motor is now running at its expected rate. In addition toevaluating motor speed, the microcontroller 60 further stores the numberof “ticks” it has commanded the motor to move during the entire motormovement operation in a separate internal register. Thus, from thebeginning of a motor movement command to the end, the microcontrollermaintains a record of the total number of ticks the motor has movedthrough. This internal register is available for periodic interrogationby a separate control unit which, in a manner to be described furtherbelow, can translate the tick count into telescope angular displacementabout an axis and, thus, the position vector of the telescope system.

[0078] In addition to commanding motor movement and evaluating opticalencoder feedback signals, the microcontroller 60 may maintain thelast-commanded motor motion in a data field defined in RAM memory. Thislast-commanded motor motion (the delta from the next-most previous motormotion command) is maintained in RAM and is also available for access bya system controller by providing the appropriate memory access commandto the microcontroller 60. Thus, the motor control electronicscomprising the electronics package 50 of the present invention can beseen to comprise means for acquiring, storing and recalling motorposition information of its corresponding motor and, thus, the positionof the telescope with respect to the corresponding axis.

[0079] An additional feature of the motor control circuitry comprisingthe electronics package 50 is its ability to intelligently evaluate thecorrespondence between a motor movement command and actual motor motionas read from the optical encoder system 54. In particular, themicrocontroller 60 includes firmware that evaluates a motor PWM pulseagainst ticks received from the optical encoder system 54 in order todetermine that the motor is, indeed, moving. A PWM threshold is setwithin the firmware such that if the PWM threshold is reached withoutthe microcontroller's having received any corresponding motion ticksfrom the optical encoder system, the motor is deemed “locked” or“burnt-out” and the microcontroller ceases to issue any further motioncommands until reset. Thus, it will be seen that the circuitrycomprising the electronics package 50 includes means allowing for anintelligent evaluation of motor PWM commands versus encoder movementresponse metrics in order to determine possible motor lock or burn-out.

[0080] An additional feature implemented in the exemplary electronicspackage 50 is an ability to adaptively tune the brightness of theoptical encoder LED diode 62 in order to provide for optimal squarenessand amplitude characteristics of the photodetector signal received bythe microcontroller 60. Specifically, LED brightness is adaptively tunedby switching one or more of five parallel-connected resistors into theLED current path between V_(cc) and a microcontroller input. Fiveresistors, 65 a through 65 f, are parallel-connected in common to theLED diode 62 at one end. The other end of each of the resistors, 65 a-65f, are connected to respective I/O pins (B2 through B7) comprising the Bport of the microcontroller 60. One or more of the resistors areselectively incorporated into the LED circuit by selecting theirrespective I/O pins as active.

[0081] LED brightness is considered optimized when a particularphotodetector output signal is evaluated as “on” approximately 50% ofthe time and “off” approximately 50% of the time. This condition obtainswhen the amplitude of each photodetector signal is such that it at leastexceeds the 2.0 volt threshold and is not sufficiently strong that it“bleeds” over the 0.8 volt “off” threshold. In other words, if thesignal amplitude is too low, the photodetector is not able to “turn on”.Conversely, if the signal amplitude is too high, i.e., the signal issaturated, the photodetector will not be able to “turn off”.

[0082] LED brightness is optimized by a firmware routine that is invokedduring an initialization procedure when the telescope system isstarted-up. Specifically, as depicted in the flow diagram of FIG. 8, themicrocontroller 60 first causes its associated motor to spin-up and moveat a pre-determined speed in a pre-determined direction, for apre-determined period of time. During this period, the microcontroller60 evaluates the output of a single one of the photodetectors anddetermines the effective duty cycle of the photodetector output signal.

[0083] If the perceived signal duty cycle was such that thephotodetector is “on” for a longer period of time than it is “off”, themicrocontroller concludes that LED brightness is greater than a desired,nominal value. In contrast, if the effective signal duty cycle is suchthat the photodetector is “off” for a longer period of time than it is“on”, the microcontroller concludes that LED brightness is lower thanits desired, nominal value. In response, resistors 65 a through 65 f areselectively enabled into the LED circuit. Following each resistorreconfiguration, the microcontroller again evaluates the effective dutycycle of photodetector signal until the effective duty cycle reaches thedesired 50% point. Once the desired LED brightness characteristic hasbeen achieved, the microcontroller 60 reviews the register statecorresponding to the B2 through B7 inputs. The register state for eachpin will have a particular value depending on whether the I/O for thatpin is active, inactive or tri-state. The register state defining thepin activation configurations required to return the necessary detectoroutput characteristics is passed, as an initialization I/O configurationvalue to an external system controller where it is stored innon-volatile memory for future reference. Alternatively, the I/Oconfiguration of the microcontroller required to return the necessarydetector output characteristics might be saved into themicrocontroller's REM memory as an I/O configuration value from where itmight be retrieved upon interrogation by an external system controller.Regardless of how saved and where it eventually resides, the I/Oconfiguration value is available to be passed to the motormicrocontroller each time the telescope system is initialized. The I/Oconfiguration value need only be obtained once, when the telescopesystem is first set up for use. The I/O configuration may, however, bereobtained and/or recalculated upon a user's initiative, in order toaccount for the gradual roll-off in LED output strength over longperiods of time. This would be useful to observers who use theirtelescope systems on an almost continuous basis and who require thegreatest precision in automatic motor control performance.

[0084] Thus, it will be understood that the microcontroller 60, incombination with resistors 65 a through 65 f, the LED diode 62 andphotodetector transistors 63 and 64, comprise means for adaptivelytunning LED brightness characteristics in order to obtain optimalphotodetector output signal squareness and amplitude characteristics.Optimal output signal characteristics are an important feature of thepresent invention since it enables motor speed and direction evaluationsto be made with a significantly greater degree of precision and accuracythan with conventional systems.

[0085] One particular embodiment of a hand-held control unit suitablefor use in combination with a semi-intelligent motor assembly isdepicted in FIGS. 5a and 5 b. FIG. 5a is a front view of the exteriorportion of a semi-intelligent drive motor motion control unit 70illustrating the various function keys that might be used by a user ofthe telescope system in order to command a telescope to move throughvarious evolutions. The motion control unit 70 comprises a hand-held,self-contained, computer control unit, enclosed within a functionalhousing. The motion control unit is operational as a dual-axis motordrive corrector which enables telescope axis motor motion, from the verysmall tracking corrections necessary for long exposure astrophotographyat sidereal rates to the very fast slewing movements required for newobject acquisition. The motion control unit supports motor movementcommands for microslewing a telescope to, and for precision centering ofa telescope onto, selected celestial objects. In addition, the motioncontrol unit 70 is able to command certain special movement functionssuch as selecting various drive rates for the telescope motors,adjusting an optional electronic focuser, and the like.

[0086] Direction keys, labeled with directional arrows indicatingmovement directions (up, down, left and right) enable a telescope systemto move, or microslew, in the specified direction at any one of aplurality of allowable, settable speeds. A speed key 72 is used tochange a speed at which the telescope system is moved by depressing thekey at the same time that one of the direction keys is being depressed.As was described previously, the number of allowable speeds which can becommanded to a semi- intelligent motor assembly according to theinvention, is limited only by the number of speed bits comprising thespeed and direction command. In the particular embodiment beingdescribed, the number of settable speeds that can be commanded to thesemi-intelligent motor assembly is arbitrarily limited to four. At thisjuncture, it is important to mention that these settable speeds refer totelescope movement commanded by an observer that interrupts nominaltelescope tracking motions, conducted at the well understood siderealrate.

[0087] The four speeds selected for implementation in the illustratedembodiment range from the top speed of telescope motion, to a speedslightly in excess of the sidereal rate. The top speed corresponds totelescope displacement of from about 40 to about 9° per second. Topspeed is particularly useful for slewing the telescope to the vicinityof new object which an observer desires to acquire. A second speedcorresponds to about 0.75° per second of telescope motion and is usefulfor centering a selected object in a wide-field eyepiece. A third speedcorresponds to about 32× the sidereal rate (about 8′ of arc per second)and is useful for centering a selected object in a high-power eyepiece.The slowest settable speed is about 4× the sidereal rate (about 30′ ofarc per second and is typically used for precision centering and forguiding the telescope system during astrophotography.

[0088] Each of the individually selectable speeds are associated with acorresponding speed indicator LED which illuminates when that particularspeed has been selected. For example, a first LED 74 illuminates whenthe selected speed is the top, a second LED 76 illuminates when theselected speed is the 0.75° per second rate, the third LED 78illuminates when the selected speed is 32× the sidereal rate and thefourth LED 80 illuminates when the selected speed is 4× the siderealrate. Thus, the currently selected speed is indicated by the speedindicator LED proximate the speed key 72 and depressing the speed key 72increments the selected speed to the next speed, illuminating theappropriate speed indicator LED.

[0089] Focus control keys 82 and 84 are provided to enable the motioncontrol unit 70 to control the operation of an optional electronicfocuser which may be coupled to the focusing ring of a telescope viewfinder. Images appearing in the view finder may be focused by depressingthe in 82 or out 84 focus keys, causing a “DIRECTION AND MOVE” commandto be issued to an auxiliary focusing device over an auxiliary bussystem, in a manner to be described in greater detail below.

[0090] A “mode” key 86 may be used to define certain special functionoperations, such as tracking rate changes, direction reversal, mountconfiguration identification, and the like. For each mode functioncapable of definition by the system, the LED bank indicates which of thechosen mode functions are operative at any given time. For example, whenpower is first applied to the motor control unit, all four LEDs arecaused to blink rapidly, indicating the unit is ready for operation.Depressing any key on the housing causes the first LED 74 to becomesteady, while the remaining LEDs turn off.

[0091] In order to select mount configuration (Alt-Az or equatorial),the user depresses and holds the mode key 86 until both the first andsecond LEDs 74 and 76 burn steady, while the third and fourth LEDs 78and 80 return to blinking. This action places the motor control unit inAlt-Az mode. To set the system into equatorial mode, the speed key 72 isdepressed once for Southern Hemisphere operation, and twice for NorthernHemisphere operation. Depressing the speed key a third time returns thesystem to Alt-Az mode. Following the mount configuration mode choice,the user depresses the mode key 86 until only the first LED 74 is lit.The unit then exits the mode function and activates the direction keys.If equatorial mode was chosen, the drive motors are now set to trackobjects at the sidereal rate.

[0092] The tracking rate of a telescope system may also be changed, in0.5% increments from the default sidereal rate, by accessing a trackingspeed mode function through the mode key 86. To do so, a user depressesthe mode key until the mode function shows active on the LED bank (LEDs74 and 76 “on” steady, LEDs 78 and 80 indicating the tracking mode lastchosen). Depressing the “in” key 82 causes the tracking rate to increaseby 0.5% and causes the fourth LED 80 to burn steady. Depressing the“out” key 84 causes the tracking rate to decrease by 0.5%. The third LED78 is caused to burn steady to so indicate. In order to exit thetracking rate change mode, the mode key 86 is again depressed, whichreturns the telescope to normal operation.

[0093] The internal construction of the semi-intelligent drive motormotion control unit 70 is illustrated in the schematic diagram of FIG.4b. As can be seen, the operational focus of the motion control unit 70is an EPROM/ROM based 8-bit microcontroller 88 exemplified by thePIC16C54, manufactured and sold by Microchip Technology, Inc. Thefunction keys described above in connection with FIG. 4a, provide inputsto the microcontroller 88 which, in response, develops control outputsignals which are directed to an 8-pin output header 90 having a pinconfiguration which corresponds to the 8-pin RJ11 connector (44 of FIG.3b) of the electrical interface junction panel, to which the motioncontrol unit 70 is intended to be connected. In response to the variousdirection, speed, focus and mode commands input to the microcontroller88, the microcontroller develops and outputs control signals for thealtitude motor (ALT CLK and ALT DATA), the azimuth motor (AZ CLK and AZDATA), and a control signal pair for the auxiliary bus (AUX CLK and AUXDATA). Movement, speed, focus and mode commands are received by themicrocontroller 88 and appropriate output control signals are developedthereby in accordance with a software or firmware program hosted by themicrocontroller 88 and conventionally stored in an internal memory spacesuch as a programmable ROM memory.

[0094] In addition to direction, speed, focus and mode commands,microcontroller 88 is adapted to differentiate between Northern andSouthern hemisphere operations and between equatorial/Alt-Az trackingmodes. A pair of jumpers are provided, with the first jumper 92differentiating between Northern and Southern hemisphere operations byits presence or absence, respectively. Southern hemisphere operation isdefined by the presence of a jumper in the first jumper position 92which completes the electrical short and asserts an I/O active state onboth the RTCC and B6 inputs. For Northern hemisphere operations, thejumper is absent from the first jumper position 92 putting the RTCCinput in an I/O inactive state.

[0095] Likewise, equatorial and Alt-Az operational modes aredifferentiated by the presence or absence of a jumper in the secondjumper position 94, respectively. Alt-Az mode is defined by shorting thejumper position and thereby asserting an I/O active state on the RTCCand RBC inputs. Equatorial mode is indicated by an I/O inactive state onRTCC while the B7 input remains active.

[0096] With regard to communication between microcontroller 88 of thecontrol unit and the microcontroller 60 of the semi-intelligent motorassembly, commands are provided in serial fashion to thesemi-intelligent motor assembly in accordance with a packetcommunication protocol, wherein each command packet comprises one ormore bytes of information and with each information byte beingsequentially clocked into the receiving microcontroller, bit-by-bit, bya serial clock signal. In accordance with practice of principles of theinvention, each semi-intelligent motor assembly is directly coupled tothe control unit's microcontroller 88 via a two-wire serial interfaceconnection through the control unit's header 90 and, thence toappropriate I/O pins of the microcontroller 88. Thus, information beingcommunicated between a control unit and a motor assembly need not bepreceded with header information. However, since the auxiliary serialinterface is able to host a multiplicity of auxiliary apparatus,information being communicated between a control unit's microcontroller88 and a particular piece of auxiliary apparatus needs to be preceded byan address header in order to identify the information's intendedrecipient.

[0097] With regard to motor motion commands, these commands are issueddirectly to the motor assembly's microcontroller over the correspondingtwo-wire serial interface. Motor motion commands, more correctly termedstep rate commands, are identified, in hexadecimal, as (00h) andcomprise three bytes of information. The step rate is defined as thenumber of steps or “ticks” that occur approximately every 6milliseconds. The format is a two's compliment number with the firstnumber representing the whole steps or “ticks” and the next two bytesrepresenting the fractional portion thereof. Each step rate commandincludes a sign (+/−) which determines the direction of motor motion.

[0098] A second step rate command, denoted (01h) in hexadecimal isformatted substantially identically with the (00h) command but is usedfor step rates greater than the 2× the sidereal rate. Additionalinformation communicated between the control unit microcontroller andthe motor assembly microcontroller include a “change error count”command (02h) which commands a one time change of the motormicrocontroller error count register. A “set LED position” (03h) commandsends out the I/O configuration byte which has been stored for thatparticular motor assembly in order to optimize its photodetectorperformance. A “find LED position” (04h) command is issued to the motorassembly when it is desired that the motor assembly finds the best LEDcurrent in order to optimize photo detector performance. A “get LEDposition” (09h) command instructs the motor assembly to write out theI/O configuration byte that corresponds to optimized photo detectorperformance.

[0099] Additional commands, such as “turn on motor in positivedirection” (06h) and “turn on motor in negative direction” (07h) arealso provided by the control unit to the motor assembly'smicrocontroller. A “status” (08h) command is read from the motorassembly's microcontroller the “status” command is typically 3 bytes inlength and further includes an additional flag bit. The first two bytesof information comprise the determined change in motor position sincethe last status read. The next byte comprises the PWM pulse count whichis used to determine whether or not the motor is in a stall condition.The final bit, the flag bit, an illegal encoder flag which indicatesthat an encoder “tick” was missed during the current motor positionchange. This bit is typically reset after a data read, as is thedetermined motor position information.

[0100] Those familiar with the internal construction and operationalprogramming of a PIC16C5X series microcontroller will be able toroutinely develop additional applications and command sets suitable for,for example, controlling LED operation, developing a digital clock, orcontrolling a keypad. All that is required in practice of principles ofthe invention, is that the control unit microcontroller be able tocommunicate with one or more motor assemblies so as to command, atleast, motor speed and direction changes which the motor assemblyexecutes without further intervention on the part of the control unit.This distribution of intelligence allows both the motor assembly and thecontrol unit to be implemented using relatively simple components, witheach respective apparatus being responsible for a particular set offunctions; the control unit translating keypad input into motor motioncommands, the motor assembly receiving the motor motion commands andcausing the required amount of telescope motion about its axis. Commandsand status information are communicated between the control unit and themotor assembly via a two-wire serial interface in accordance with apacket communication protocol. The control unit is able to determinethat its commands have been appropriately executed by evaluatingreturned status information from the motor assembly. Appropriatetelescope motion in response to a motor movement command is ensured byevaluating feedback signals developed by an optical encoder systemmechanically coupled to the motor and electronically evaluated by themotor assembly's microcontroller unit.

[0101] Thus, in accordance with the invention, the hand-held controlunit and motor assembly, in combination, suitably provide means fordistributing motor control intelligence, with the intelligencepartitioned into first and second portions, the first portion responsiveto user input and for translating that input into suitable commandsignals, the second portion responsive to the command signals andtranslating the command signals into signals suitable for use by a motordriver circuit in effecting motor motion. The two portions of thesystem's distributed intelligence are coupled together over a two-wireserial interface allowing bi-directional communication of data andcommand signals between the two portions over a thin, flexible cable.

[0102] An additional embodiment of a hand-held control unit suitable forintelligent control of a telescope system according to the invention, isillustrated in FIGS. 6a and 6 b. FIG. 6a depicts the exterior of anintelligent telescope system controller as it would appear to a systemuser, while FIG. 6b illustrates, in semi-schematic block diagram form,configuration of the electronic system components which providefunctionality to the controller 100.

[0103]FIG. 6a is a front view of the exterior portion of an intelligenttelescope system controller 100 illustrating the various function keysthat are used by a user of the telescope system in order to command atelescope to move through various evolutions. The intelligent controller100 comprises a hand-held package which functions as a full-spectrumcontrol unit capable of intelligently defining and commanding motormovements required for astronomical observations, as well as forimplementing various pre and post processing features in a mannersimilar to a microcomputer.

[0104] The intelligent controller 100 suitably comprises an LCD displayscreen 102, capable of displaying text, numeric and graphic output datathat might be consulted by a user in operating the telescope system. Allprompts, user queries, confirmation messages, and the like, aredisplayed on the LCD screen 102. Telescope-motion direction keys 112,labeled with directional arrows, indicating up, down, right and left,provide the necessary inputs for enabling the telescope system to move,or microslew, in the specified direction, at any one of a number ofallowable, settable speeds. As was described previously, the number ofallowable speeds which can be commanded to the semi-intelligent motorassembly according to the invention, is limited only by the number ofspeed bits comprising the speed and direction command. In the particularembodiment being described, the number of allowable speeds that can becommanded to the semi-intelligent motor assembly is 8, with one of the 8allowable speeds being reserved for the motor stop command. Motor speedchanges are effected by entering numerical values on a numeric keypad104. To change or define a particular motor speed, a user presses andreleases the desired numeric key corresponding to the desired speedrange (1 being the slowest, 9 being the fastest). Once the desired speedis selected, the desired motion direction key 112 is depressed and thesystem commands the corresponding semi-intelligent motor assembly tomove the telescope system at the desired speed, in the desireddirection.

[0105] Scroll keys 106 and 108 are provided in order that a user mayscroll through a data base listing or through available menu optionsthat might be shown on the LCD display screen 102. A “?” key 110,disposed between the scroll keys 106 and 108, accesses an internal“help” file and, when depressed, causes the LCD screen 102 to display abrief description of the selected menu item on the first line of thedisplay. An enter key 113 selects a file menu or option, or is used todefine the completion of an entry made in response to a system prompt. Amode key 114 allows a user to exit a current menu to return to aprevious menu and a go-to key 115 commands the telescope system to slewthe telescope to an object chosen from an internal celestial object database listing, for example.

[0106] The internal construction of the intelligent telescope systemcontroller 100 is illustrated in the schematic diagram of FIG. 6b. Ascan be seen from the figure, the intelligent controller, indicatedgenerally at 100, suitably comprises a dual processor system, with thedual processing functions implemented by a first, general purposemicroprocessor 120 exemplified by the 68HC11, a member of 68HCxx familyof microprocessors manufactured and sold by Motorola, and a second,purpose configured microprocessor or microcontroller 121, exemplified bythe PIC16C57 microcontroller manufactured and sold by MicrochipTechnology, Inc.

[0107] The general purpose microprocessor 121 is coupled to a 16-bitaddress and data bus (AD[0,15]) and an 8-bit data bus (D[0,7]), whichallow the microprocessor 121 to communicate with a programmableread-only memory (ROM) memory circuit 124 and a random access memory(RAM) 126. Further, the four most significant bits of the data bus(D[4,7]) are coupled to the system's LCD display driver circuit 127 toprovide an interface between the microprocessor 121 and the system's LCDdisplay 120. As will be described in greater detail below, themicroprocessor 121 is responsible for implementing the top-levelfirmware architecture of the system according to the invention and forexecuting loadable application software routines pertinent to theexemplary intelligent telescope system.

[0108] Programmable read-only-memory circuit 124 is preferablyimplemented as a FLASH programmable ROM and is provided in order to hostthe instruction set for downloaded applications and software routines,data tables such as a stellar object position data base, the Messierobject catalog list, an earth-based latitude/longitude correspondencetable, and the like. Although described as an FPROM, the ROM memory maybe implemented as an EEPROM, or any other type of programmablenon-volatile memory element. Indeed, the ROM 124 might be implemented asan external mass storage unit, such as a hard disk drive, a programmableCD-ROM, and the like. All that is required, is that the memory 124 beable to be written to, in order that its hosted data bases and tablesmay be updated, and be non-volatile, in order that its hosted data basesand tables be available to the system upon boot-up or power-on-reset.

[0109] Microprocessor 121 is further coupled via a 2-bit serial-typecontrol bus 123 to the microcontroller 122 which, in turn, is coupledvia a multiplicity of interface signal lines to the various functionkeys (indicated generally at 132) which comprise the operator/systeminterface for this system. In this respect, the microcontroller 122functions as the system I/O and interface controller which translatesuser input taken from the keypad, and provides command and controlsignals, derived from the user input, to the system microprocessor overthe serial interface 123. The serial interface bus 123 is furthercomprised of two signal lines, CLK and DATA, which function much thesame as the 2-wire serial interfaces between a motor assembly and theparticular embodiment of a control unit described in connection withFIG. 5b. The interface bus 123 is bi-directional and command and datasignals are communicated in accordance with a packet transmissionprotocol.

[0110] The system microprocessor 121 is further coupled to RS-232interface port circuitry 128 via an additional 2-wire (supportingconventional Tx and Rx signal lines) serial bi-directional interface bus133. The RS-232 port circuitry 128 is in turn coupled to an RS-232interface connector 129, through which bi-directional communicationbetween the microprocessor 121 and external information sources such asa personal computer (PC), a World Wide Web interface link, and the like,may be effected. Indeed, the RS-232 port 128 may be configured tocommunicate with a similar RS-232 port comprising another, separateintelligent controller system operating in connection with another,separate telescope system. It will be understood that, when operatingunder appropriate I/O control application firmware, the microprocessor121 in combination with the RS-232 port 128 provides means for quicklyand easily interfacing the system to an external source of programmingcode, data or other information that a user might desire to incorporateinto the operating instructions or data tables comprising theintelligent controller of the present invention.

[0111] Likewise, the microcontroller 122 is coupled to a bundled serialinterface connector 130, suitably comprising an 8-pin RJ11-typeinterface suitable for connection to the 8-pin receptacle (44 of FIG. 3aand 3 b) of the electrical interface panel (30 of FIG. 3a and 3 b). Theserial interface connector is configured to support communicationbetween the microcontroller 122 and two telescope axis drive motorassemblies along with a plurality of auxiliary devices, over respective2-wire serial interface busses. So configured, the PIC16C57microcontroller 122 will be understood as interfacing between the userI/O interface keys 132 and the 68HC11 microprocessor 121, to generatecommand and control signals suitable for use by a semi-intelligent motorassembly and/or an auxiliary device, such as an electronic focusingsystem, and provide such command and control signals to the serialelectrical interface panel (30 of FIG. 3a and 3 b) for routing to theirappropriate destination. A crystal oscillator circuit 135 is furthercoupled between the microcontroller's clock inputs (OSC1 and OSC2) andprovides an 8 Mhz operational clock signal to the microcontroller 122.

[0112] Power is also received, from an external power supply, throughthe serial interface connector 130. The power and ground pins arecoupled to a power supply circuit 134. The supply circuit 134 ispreferably implemented as a voltage regulator and functions to conditiona 12 Volt (for example) supply input to the reduced voltage levelsrequired by modern integrated circuits. A pertinent consideration givento the power supply circuit 134 is its need to provide suitable supplyvoltages and currents for a plurality of LEDs which populate the system100. In particular, the LCD display 120 is backlit by an arrangement ofLEDs which are configured in a circuit 136 and disposed about thedisplay screen in a novel fashion to provide uniform illumination of theentire surface of the display screen. Operation of the LED circuit 136is controlled by the microcontroller 122, and its configuration will bedescribed in detail below.

[0113] In accordance with the present invention, the 68HC11microprocessor 121 performs the high level application softwareexecution tasks and the associated data handling and numericalprocessing, in order to define the appropriate motion commands to beprovided to the PIC16C57 microcontroller 122. The microcontroller 122receives motion command inputs from either the microprocessor 121 or theuser interface keys over interface bus 123 and suitably processes thereceived motion commands into command and control signals suitable foruse by a motion control processor.

[0114] To complete the system, and to give the microprocessor 121 somemeans of performing time calculations appropriate to celestial motion, areal time clock 138 is provided and is coupled to a clock input of themicroprocessor 121, as well as being coupled to a clock input of themicrocontroller 122. The real time clock 138 is preferably implementedas a precision timing reference clock signal generator, such as a UTCclock, that is used by the microprocessor 121 to calculate sidereal timeintervals and preferably resides as an integral component of the controlunit 100. Alternatively, the clock 138 might be implemented as aseparate, off-board integrated circuit comprising a conventional UTCclock which communicates with the system over the RS-232 interface, oran on-board UTC clock and follow-on circuitry for converting UTC timeintervals to sidereal time intervals prior to providing a timingreference signal to the microprocessor 121.

[0115] Thus, it should be understood that the intelligent telescopesystem controller 100 suitably comprises a means for adding fullintelligence to a telescope system which includes semi-intelligent motorassemblies in accordance with the present invention. The intelligenttelescope system controller performs this function by bifurcating thesystem's processing and control functions into a first, sub-systemcomprising a microprocessor operative for system data processing, and asecond, microcontroller system for implementing I/O control. Systemintelligence is maintained up-to-date, by allowing “new object”loadability through an RS-232 port. System software, updated celestialobject catalog tables, and the like, may be loaded into the systemthrough the RS-232 port from a PC, an attached disk or diskette drive, aweb site, a separate intelligent telescope system controller inaccordance with the invention, and the like.

[0116] In particular, a user may “clone” his system's applicationprograms and his system's database contents into another user's systemusing the RS-232 port to effect bidirectional communication.Alternatively, the user may receive program and data information from asecond intelligent telescope system controller, thus “cloning” thatcontroller into his own, over the RS-232 interface. The “clone” functionis implemented by accessing the various user interface keys provided onthe exterior of the controller 100. For example, the user might depressthe mode key 114 until a system I/O menu appears in the controller's LCDdisplay. The user might then scroll through the menu using the scrollkeys 106 and 108 until a “clone” menu option appears in the screen. Ifsuitable connections are made between two intelligent system controllersaccording to the invention, and if the appropriate input and outputstates are set for each controller (the controller being cloned outputsdata), the user might depress the enter key 113, initiating the process.

[0117] Several other system utilities are supported by themicroprocessor 121 of the intelligent telescope system controlleraccording to the invention. For example, the system may be placed in astate of suspension by invoking one of two, reduced functionality, modestermed “sleep mode” and “park mode”. Since, as was described above, thesystem and timing reference is preferably a crystal controlled clock 130coupled to the microprocessor 121, an external time-of-day input isrequired in order that the system can correctly calculate the system'slocal hour angle and, thus, the celestial sphere's rotational state withrespect to a specific observer. When the system is placed in “parkmode”, all system orientation parameters (to be described subsequently)are saved in the buffer/scratch pad RAM 126, from whence they may berecalled when a user desires to perform additional observations. Oncethe system is oriented and has been placed in “park mode” all that isrequired is that the user input a time-of-day datum for the telescopesystem to precisely know (or, more correctly, remember) its orientationwith respect to the sky.

[0118] In “sleep mode” the system again remembers its orientationparameters, but maintains the clock 138 in an operative condition whilereducing power to the remaining system components to maintenance levels.Thus, in “sleep mode”, the system is ready to “wake up” at any time theuser gives it an operation command.

[0119] Beyond support of system utilities, the intelligent telescopesystem controller is also able to support a multiplicity of auxiliarydevices that might be coupled to the telescope system in order toenhance its capabilities. Pertinent such devices include an automaticfocusing unit, a clock and date module, a speech recognition module andan associated audio output module, an automatic alignment tool (tubeleveler and/or axis planarizer), a global positioning system (G.P.S.)module, a photometer, an autoguider, a reticle illuminator, a cartridgereader station (for courseware, new revisions, new languages, objectlibraries, data storage) and the like. Each auxiliary device is coupledto the system, in daisy-chain fashion, over the AUX DATA and AUX CLKsignal lines comprising a serial auxiliary bus system. As was the casefor the Alt (Dec) and Az (RA) serial busses coupled between thecontroller and the motor assemblies, the auxiliary bus is a 2-wireserial communication interface and further includes a supply voltageline, supplying 6-18 and preferably 12 Volts of power, and a groundpotential line.

[0120] The 2-wire interface comprises a bi-directional data line whichsupports data communication using a packet transmission protocol, and aclock line which supports a clock signal typically sourced by the busmaster, in this case, the system controller. Because the auxiliarydevices are daisy-chain configured, each device is provided with aunique bus address so that commands can be efficiently processed by theparticular device being accessed. In accordance with the presentinvention, bus addresses are expressed as a binary numerical valuedefining an address byte. Thus, the system is able to communicate withup to 256 separate addresses and, therefore, 256 separate devices.However, as will be explained below, one address, the “byte zero”address, is reserved as a broadcast address, indicating that thefollowing command or commands are to be executed by all devices coupledto the bus.

[0121] All communication transactions over the auxiliary interface busare performed in accord with a packet transmission protocol. All busactivity begins with a bus master (typically the system controller)initiating a communication packet to a selected target device. Once themaster-to-target communication is completed, the target device returns amessage or status communication packet back to the bus master. Asillustrated in the simplified interface protocol packet content diagramof FIG. 12, all packets begin with “count byte” which defines the numberof bytes comprising that particular initiating or response packet. Inthe case of an initiating packet, the second byte comprises the “addressbyte” for the particular target device which will execute the command,and is followed by a “command byte” which defines the operation to becarried out. “Intermediate bytes”, unique to each device, follow the“command byte” in the case of an initiating packet, or the “count byte”in the case of a response packet. A “last byte” is also unique to eachdevice and is the final byte of an initiating packet transmitted by themaster. Optionally, a target device may be configured to transmit a“last byte” as the final byte of a response packet.

[0122] The clock signal is driven by the bus master for all informationtransfers, regardless of the direction of data flow. In addition, thebus master may temporarily relinquish control of the bus and designate aparticular device to temporarily assume the bus master role inthird-party data transfer operations, such as between a CCD imager and adisk drive. All auxiliary devices are “I/O hot” in that all devices areconstantly “snooping” the bus and can evaluate all packets transmittedthereon. Once a device determines that a packet header contains itsaddress, the rest of the packet is clocked into its I/O registers andthe command is then executed.

[0123] Certain broadcast commands are common to all auxiliary devicesand are identified by a “broadcast address”, indicating that all devicescoupled to the bus are to execute the following command. Exemplarybroadcast commands include a “bus reset” command which is used toperform a soft reset of the bus and the “sleep” command which placeseach device in its own particular low-power mode. An “inquiry” commandis not specifically a broadcast command, but is nevertheless directed toall devices on the bus; albeit sequentially. The “inquiry” command isused to determine the presence of a device on the bus. The initiatingpackets cycle through the bus addresses, with devices populating the busreturning a status byte identifying the device revision number or moduletype, as their addresses are received.

[0124] The full spectrum of auxiliary device command sets can be easilyimplemented in the intelligent system controller (100 of FIGS. 6a and 6b) because of the capability range of its microprocessor (121 of FIG.6b). It will be understood, that the full spectrum command set may beincorporated in the microprocessor by a reasonably proficient programmermaking the intelligent system controller 100 capable of supporting thefull spectrum of auxiliary devices. A reduced set of auxiliary devicecommand sets are implemented in the semi-intelligent system controller(70 of FIGS. 5a and 5 b) because of the relatively limited capabilitiesof its microcontroller 88, with respect to the capabilities of the fullyintelligent system. Thus, only certain auxiliary devices are supported,such as an electronic focusing unit, in the semi-intelligentconfiguration, while the capacity for upgrading the system to a fullyintelligent configuration remains unimpaired. Indeed, the serialauxiliary interface bus provides a particular enabling feature forsystem upgrade capability by virtue of its simplicity and the inherentexpandability of the 2-wire serial bus concept. Adding capability to thetelescope system of the invention, is as uncomplicated as merelycoupling additional devices to the bus. The bus, then, provides theframework within which intelligence and capability are added, subtractedor modified on a piece-by-piece basis.

[0125] Each component coupled to the system comprises its ownoperational intelligence and requires only a serial command interfacewith a controlling entity to perform its designated function. Since eachcomponent comprises sufficient intelligence (processing power) toexecute its tasks without higher level supervision, the controllingentity is free to execute application programs, perform complexarithmetic calculations, maintain database entries, and the like.

[0126] Primary control of an automated telescope system with distributedintelligence, in accordance with the present invention, is provided by afully intelligent telescope system controller 100. Substantially allfunctions of an automated telescope system can be implemented throughthe keypad portion of the controller 100 by depressing the variousalpha, numeric and function keys provided thereon. Once the automatedtelescope system has been appropriately aligned, as will be described ingreater detail below, an object menu library, stored in a dedicatedmemory space provided in the controller, is used to automatically slewthe telescope system to any particular celestial (or terrestrial) objectan observer desires to view or photograph. However, prior to beginningan observation and, indeed, during initial setup of the system, a usermust first initialize the system by entering certain information inaccordance with an initialization, or setup, procedure which can be bestunderstood with reference to the initialization procedure flow chart ofFIG. 8.

[0127] After each of the individual components comprising the telescopesystem are connected together through the electronic interface junctionpanel (30 of FIG. 2), the intelligent system controller 100 is pluggedinto the control unit port (44 of FIGS. 3a and 3 b) and power isprovided to the system. Following “power-on-reset”, a warning message isdisplayed on the LCD screen 102 of the system controller 100, warningthe user not to look directly at the sun through the telescope. Thewarning remains on the LCD screen 102 for a period of a few secondsfollowing which the system controller prompts the user to enter thecurrent date, by entering the appropriate figures in a formatted datefield. An exemplary date field might appear as “01 Jan. 1999”. Numericvalues, such as the date and year are entered by pressing thecorresponding numeric keys of the numeric keypad 104 when prompted to doso by the system. The current month is entered by scrolling through alist of months using the up 106 and down 108 arrow keys provided forthat purpose. In particular, the date cursor automatically jumps to thenext space once a particular numeric value is entered. If a mistake ismade during entry, the right or left directional keys may be depressedin order to move the cursor backward or forward until it is positionedover the incorrect entry. The correct entry may then be made bydepressing the appropriate numeric key on the numeric keypad 104.

[0128] The numeric keys are used to enter the current day. Then, the up106 and down 108 scroll keys are used to cycle through the list ofmonths. When the current month is displayed the right arrow key causesthe cursor to move to the year field into which the current year isentered using the numeric keys 104. After all of the date informationhas been correctly entered, a user depresses the enter key 113 in orderto inform the system that the current date has been entered and the datesetting procedure is now concluded.

[0129] The system then prompts the user to enter the current time. Itshould be noted that the system is operative in a 24-hour mode and,therefore, time should be entered using a 24-hour clock (i.e., 9:00 pmis entered as 21:00). As was the case with the date entry, a userdepresses the enter key 113 in order to inform the system that the timeentry procedure has been concluded. It is worth mentioning, at thispoint, that a user should enter a time just slightly ahead of thecurrent time prior to depressing the enter key. The enter key isdepressed at the exact moment the current time matches the time the userentered. This procedure is very useful in enhancing the precision of thepositioning calculations undertaken by the system, by giving the systema more precise indication of the correct time. Needless to say, the moreprecise the time indication provided to, the system, the better thesystem will be able to locate objects on the basis of their publishedright ascensions and the better the system will be able to accuratelyposition the telescope to view them.

[0130] At this point, the positioning keys 112 of the system controller100 are activated such that they may be used to move the telescope. Auser is able to either immediately proceed to using the telescopewithout further initialization data entry, or continue with data entryin order to enable additional features of the inventive system. If auser chooses to continue with initialization, a next procedure displaysthe status of a daylight savings time feature. Daylight savings time isin effect from the first Sunday in April through the last Sunday inOctober in most areas of the United States and Canada. Users arecautioned to investigate as to whether their geographic local timeconforms to daylight savings time or not. The display status is in a“negative default” condition indicating that the daylight savings timefeature is not enabled. If a user is currently in daylight savings time,the enter 113 key is depressed once which causes the display indicationto change from NO to YES. When the desired setting is displayed on thescreen, the mode 114 key is depressed indicating that the daylightsavings time procedure is concluded.

[0131] A next sequence of data entry options enables a particularlynovel orientation feature of the present invention, wherein anobserver's latitude and longitude are approximated by the latitude andlongitude of the closest city or other geographical landmark which auser may designate as reasonably approximating his observation location.For example, the next procedural step causes the LCD display 102 torequest entry of the nation, state or province, of the user's primaryobservation site. The UP 106 and DOWN 108 scroll keys are used to scrollthrough a list of various countries, states and provinces contained inthe system's database until the observer's nation, state or provinceappears on the screen. Following selection of the observer's nation,state or province, the observer is requested to select the closest cityor major geographical feature to their primary observation location byusing the UP and DOWN scroll keys to cycle through an alphabetical listof cities and geographical features. When the desired city or feature isdisplayed on the LCD screen, the user presses the enter key 113 toinform the system that the virtual location procedure has beenconcluded. The geographical coordinates (latitude and longitude) of theselected site are then entered into system memory as a firstapproximation observation location indicia which is used in combinationwith the current time to orient and align the telescope system for fullyautomated use.

[0132] This virtual location procedure is enabled by a database tablecomprising a multiplicity of alphabetically listed geographic locationswith each associated to their known latitude and longitude coordinates,as depicted in FIG. 9. FIG. 9 illustrates a partial database listing ofan exemplary top-level location table and a sub-level database listingfor locations contained within the indicated California entry. Thelocation database listing is typically stored in the system's ROM memory124, but might alternatively be stored in an external disk drive, onfloppy diskette, or some other such mass storage device so long as thelocation database listing is stored in some form of non-volatile memorysuch that it may be accessed at need upon system power-up.

[0133] The need for such a virtual location procedure is evident whenone considers that the location of a particular celestial object in thenight sky, at any given time, is solely a function of the observer'slatitude and the observer's local hour angle displacement from thecelestial meridian, in turn a function of the observer's longitude andthe observer's local time-of-day. Thus, once an observer's latitude andlongitude are known, and the time-of-day (expressed in universal timecoordinates) is known, the observer has all of the information necessaryto compute the relative bearing in either altitude and azimuth ordeclination and right ascension of any celestial object whose absolutecoordinates are known. When an observer enters a reasonableapproximation of his latitude and longitude, and enters his local time,the system is able to reasonably approximate the orientation of thenight sky with respect to that observer. As will be described in greaterdetail below, further corrections may be made to this “firstapproximation” orientation procedure in order to more precisely andaccurately define the night sky with respect to the telescope'sorientation.

[0134] Following the virtual location procedure, the system then promptsa user to enter the configuration and alignment mode to be used for thetelescope system to which the system controller 100 is coupled. Thesystem has two configuration and alignment options; Alt-Az and polar(equatorial). The choice between these two configuration and alignmentmodes is made by scrolling through the choices using the UP 106 and DOWN108 arrow keys until the appropriate configuration and alignment modeappears on the screen. When the appropriate mode appears, the userdepresses the mode 114 key thereby informing the system of theconfiguration and alignment method most appropriate for the telescopesystem. Once system configuration is determined, the controllercommences a motor test, slewing the telescope a short distancehorizontally and vertically (RA and Dec). After the motor test iscompleted, the system initialization is complete and the telescopesystem is ready to be aligned for observations.

[0135] System initialization is performed the first time that power isapplied to the system controller 100 or any time the system isaffirmatively RESET. During subsequent observation sessions, when poweris applied to the system controller 100, the controller internallyinitializes and will only prompt a user to enter a randomly selectednumber used in connection with the sun warning and, subsequently toenter the time and date. From this point, the system proceeds directlyto telescope alignment and, in addition, if the polar (equatorial)configuration and alignment model was specified during theinitialization procedure, the system controller 100 automaticallyactivates the right ascension (RA and Dec) motor subassemblies.

[0136] Since the system controller is operable to define telescopealignment with respect to both Alt-Az and polar (equatorial)configuration and alignment models, it would be appropriate to discussthe different alignment procedures associated with each of the modelsseriatim, with the Alt-Az alignment models being described first. Inaccordance with practice of principles of the invention, the systemenables the user to choose among four different alignment procedures,three of which are concerned with aligning the telescope to thecelestial sphere and one of which is used in connection with terrestrialalignment.

[0137] In a manner well understood by those having skill in the art, atelescope configured to operate in an Alt-Az mode is unable to “stop thesky” in hardware by maneuvering in equatorial coordinates. Accordingly,Alt-Az telescope configurations must “stop the sky” in software whentracking a celestial object. In contrast to a polar or equatorialmounting, which may be driven in one axis only, at a constant rate, bothaxes of an Alt-Az telescope mount must be driven at rates that vary overa wide dynamic range. Specifically, the drive rate equations for thealtitude and azimuth motors, respectively, of an Alt-Az telescopesystems are as follows: $\begin{matrix}{\frac{Z}{h} = {15\sin \quad A\quad \cos \quad \phi}} & {{EQUATION}\quad 1} \\{\frac{A}{h} = {{- 15}\left( {{\sin \quad \phi} + {\cot \quad Z\quad \cos \quad A\quad \cos \quad \phi}} \right)}} & {{EQUATION}\quad 2}\end{matrix}$

[0138] Where Z is the calculated zenith distance of an observer, h isthe observer's local hour angle (or LHA), A is azimuth (measuredWestward from the South) and φ is the observer's latitude. The rate ofchange of an object's zenith distance Z with hour angle h and the rateof change of an object's azimuth A with respect to hour angle h isdefined in units of (sidereal second)⁻¹. Thus, in order for thetelescope system to be able to adequately acquire and track a givencelestial object, it is necessary that the telescope system understandits orientation with respect to the sky such that such that anobserver's latitude and local hour angle (φ, h) can be calculated.

[0139] Over the centuries, a great deal of thought and consideration hasbeen given to various methods for determining latitude and longitudefrom an evaluation of the positions of celestial objects with respect tothe celestial coordinate system. Specifically, the field of celestialnavigation is directly concerned with mathematical methods fordetermining an observer's latitude and longitude from measurements takenof the positions of the sun, moon, planets and various known stars.Although position determination methodologies have evolved over thecenturies, they may all be conceptually viewed as defining variousmathematical means for observing and measuring the positions ofcelestial references in an earth-based coordinate system (rectangularcoordinates or altitude-azimuth coordinates) and comparing themeasurements so obtained with the positions of such celestial objectsexpressed in celestial coordinates (right ascension and declination) asare tabulated in an ephemeris.

[0140] The solution to any given problem in celestial trigonometrytherefore depends on being able to convert measurements obtained in onecoordinate system (Alt-Az, for example) in the other coordinate system(the celestial coordinate system). Coordinate system conversions arewell understood by those having skill in the art and, indeed, have alsoundergone a conceptual evolution, culminating in modern day, computerassisted, matrix transformation and rotation mathematics. Nevertheless,regardless of the coordinate systems used to express an observation andthe coordinate system used to define a universal reference, observationsmade in one coordinate system may be rotated into the referencecoordinate system using simple mathematical principles, so long as twopoints in one coordinate system correspond to the same two points in theother coordinate system such that the transformation boundaries withrespect to displacement and rotation are defined. Thus, in accordancewith generally accepted mathematical principles, two reference pointsexpressed in an Alt-Az coordinate system, for example, are a necessaryand sufficient condition for the Alt-Az coordinate system to be rotatedinto a celestial coordinate system, so long as those same twomeasurement points have a corresponding location metric in the celestialcoordinate system.

[0141] Proceeding now to the alignment methodologies in accordance withpractice of the invention, a first, “easy” alignment procedure will bedescribed in connection with the procedural flow chart of FIG. 10a.After internal initialization prior to beginning an observation session,the LCD display 102 of the intelligent telescope system controller 100displays a prompt screen requesting the user to select one of fouralignment procedures, which a user may select by scrolling through thevarious choices using the UP 106 and DOWN 108 scroll keys. A firstalignment procedure, denoted “easy” requires no knowledge of the nightsky because the system controller is able to locate its own alignmentstars based on the date and time entries provided by the user duringinitialization.

[0142] Specifically, when the “easy” alignment procedure is selected,the system next prompts the user to move the telescope (using the motionkeys 112) until the telescope is pointed North. After the telescope tubeis pointed North, a user depresses the enter key 113 to inform thesystem that the telescope tube is in its appropriate position. Next, thesystem prompts the user to level the telescope tube by adjusting thetelescope's altitude position until the altitude (or declination)setting circle is set to 0°. Pointing the telescope North and levelingthe telescope tube functions to zero-in the position encoders of thealtitude and azimuth motor assemblies. Any subsequent motion of thetelescope away from its 0,0 position allows the telescope system todirectly calculate its altitude and azimuth displacements from the 0,0reference point. Using the time and date entries presented by the user,the telescope system consults a database of well known celestial objectsand selects a particular bright object which is currently above thehorizon. The entered time and date information allows the system tocalculate whether that particular bright object has rotated sufficientlyin right ascension to bring it above the observer's horizon, while thevirtual latitude and longitude entry provided by an observer's enteringtheir closest city or geographic feature, provides the system withsufficient information regarding an observer's latitude so that it maycalculate an approximate declination value for that bright object.

[0143] Once an object (star) is identified in the database, the systemautomatically slews the telescope to the vicinity of that star bycommanding the appropriate motion from the altitude and azimuth motors.Once the telescope has slewed to the vicinity of the desired star, theobserver is prompted to center the star in the field of view of thetelescope eyepiece, using all four direction keys (112 of FIG. 6a) asrequired to center the star. When the star is centered in the field ofview of the eyepiece, the observer presses the enter key 113 and thesystem then searches the data base for a second bright-object or starwhich is displaced at least 30° from the previous star in order toincrease the accuracy of alignment procedure. Once the second star isidentified from the data base, the system automatically slews thetelescope to the vicinity of that star and once again prompts the userto center that star in the field of view of the eyepiece using thedirection keys 112 of the system controller 100. When the second star iscentered, the system calculates the position and orientation of thetelescope with respect to the night sky (the celestial sphere).

[0144] A further, truncated, alignment procedure is depicted in thealignment flow chart of FIG. 10b, in which an Alt-Az configuredtelescope is oriented to the night sky using only a single staralignment procedure. As with the previous case, a user is prompted tozero-in the motor position encoders by pointing the telescope to theNorth and leveling the telescope such that the altitude setting is at0°. The user then selects a particular star from an alphabetized stellarobject database list and presses the enter key 113, causing thetelescope to automatically slew to the vicinity of that star. The usercenters the star in the field of view of the eyepiece by depressing theposition keys 112 as required. Once the chosen star is centered in thefield of view of the eyepiece the user again presses the enter key 113the telescope is aligned for a night of viewing.

[0145] Although the telescope might technically be considered “aligned”after the user follows the above-described one star alignment procedure,the accuracy of the one star telescope alignment procedure should onlybe considered sufficient for general astronomical observations. Becauseof certain pointing errors that occur as the result of well knownastronomical perturbations, as will be described further below,additional observations and alignment steps should be incorporated intothe procedure to refine the accuracy of the initialization procedure.

[0146] Turning now to FIG. 10c, a user definable two star alignmentprocedure will now be described in connection with the illustratedprocedural flow chart. As with the previous two alignment procedures,the telescope undergoes an internal initialization prior to beginningthe observation session following which the LCD display 102 of theintelligent telescope system controller 100 displays a prompt screenrequesting the user to select an alignment procedure. If the userdesires to align the telescope with regard to two user defined celestialobjects, the user may scroll through the alignment to the two staralignment option and press the-enter key 113.

[0147] The system next prompts the user to point the telescope to theNorth, in order to zero the azimuth axis position encoders, after whichthe user depresses the enter key 113 to inform the system the telescopetube is in its appropriate azimuth position. Next, the system promptsuser to level the telescope by adjusting the telescope's altitudeposition until the altitude (or declination) setting circle is set to0°, thus zeroing the altitude motor position encoders. As was describedpreviously, all subsequent motion of the telescope away from thispre-set 0,0 position, allows a telescope system to directly calculateits altitude and azimuth displacements from the 0,0 reference point. Theuser is then prompted to scroll through an alphabetized stellar objectdatabase listing and select a particular star from the list bydepressing the enter key 113. Again, once a particular user defined staris identified, the system controller automatically slews the telescopeto the vicinity of that star. When slewing is complete, the user isprompted to center that star in the field of view of the eyepiece usingthe position keys and, when the star is centered, the user depresses theenter key. The user is then prompted to scroll through the alphabetizedstellar object data base listing and select a second particular starfrom the list. Again, the enter key is depressed indicating that theuser has selected the second star. Once again, the system controllerautomatically slews the telescope to the vicinity of the star afterwhich the user is again prompted to center that star in the field ofview of the eyepiece using the position keys. When the second star iscentered the user depresses the enter key and the system controllercalculates the absolute position of the telescope system with respect tothe night sky.

[0148] Once the absolute position of the telescope system with respectto the night sky is determined, the system microprocessor 121 is easilyable to calculate the path of any given celestial object through the skyand to develop the appropriate motor motion commands in accordance withthe above-mentioned drive rate equations, such that an Alt-Az telescopesystem can smoothly and accurately track the object, i.e., “stops thesky” in software. A celestial object's motion through the sky will,necessarily, be calculated in terms of its rate of change in bothaltitude and azimuth as a function of time. Thus, for a given timeperiod, the system microprocessor 121 is able to calculate theincremental motor step or “tick” rates required to be executed by themotor assembly so as to allow the telescope to track the object as itmoves through the sky.

[0149] With regard to the foregoing alignment systems described inconnection with the procedural flow charts of FIGS. 10a, 10 b and 10 c,it should be noted that the system controller calculates the telescope'sposition by mapping the telescope's Alt-Az coordinate system (Cartesiancoordinate system) to the RA and Dec spherical coordinate systemdefining the night sky (the celestial sphere) In particular, the systemcontroller reads the telescope's altitude and azimuth angular positions,when pointed at the selected star or stars, by reading the altitude andazimuth motor position encoder values when the user depresses the enterkey after each star has been centered in the telescope eyepiece. Fromthe telescope pointing angles thus defined, the system controllercalculates the telescope's Cartesian position vectors and resolves eachposition vector into a matrix of direction cosines. The Cartesiancoordinate matrix is mapped into a similarly defined matrix of thedirection cosines of the star or stars expressed in terms of thecelestial coordinate system, using well understood mathematicaltechniques involving matrix manipulation and rotation. The matrix ofcelestial direction cosines is generated by evaluating the RA and Deccoordinates of the star or stars identified by the user during theselection procedures.

[0150] It will be evident to those familiar with the mathematical artsthat once the same two points are identified in two different coordinatesystems, those two coordinate systems can be mathematically mapped toone another such that any further coordinates expressed in onecoordinate system are easily expressed in the other coordinate systemthrough a mathematical transform. Thus, once the telescope system isaligned with respect to the celestial sphere, further observations maybe made by merely expressing the location of a desired object in termsof its celestial coordinates. The system controller understands therelationship between the celestial coordinate system and the telescope'saltitude and azimuth coordinates, makes the proper mathematicaltransformation and drives the altitude and azimuth motors appropriatelyto point the telescope at the desired celestial position.

[0151] Once a telescope is “aligned” by use of one of theabove-described alignment procedures, the user might wish to furtherrefine the alignment accuracy of the telescope system by refining theCartesian coordinate matrix defining the telescope's altitude andazimuth position vector. As is well known in the art, certaincorrections must be applied to a celestial object's mean catalog ofposition in order to reduce it to the object's apparent position in thenight sky. When an observer plans an evening's observations, theobserver typically obtains an object's RA and Dec coordinates from anephemeris or catalog which defines the object's position in terms of thecoordinate system of a standard epoch. This is the mean position of theobject. However, the standard epoch is generally different than theepoch at the time of observation. In addition, the object's catalogposition does not include corrections for certain positional errorswhich depend upon the observation time and the particular location ofthe observer. Thus, the catalog position does not define precisely wherethe observer would likely find the desired object. Since the telescope'ssystem controller operates on an object data base which definescelestial objects according to their mean position taken from a catalog,the mean coordinates must be converted to apparent coordinates beforecommands are sent to the telescope's altitude and azimuth motors, inorder that an object may be precisely acquired and tracked.

[0152] The corrections that must be applied to a catalog mean positionin order to reduce it to apparent position are listed in the followingtable, in order of decreasing size. TABLE 1 Approx. Correction MagnitudePrecession  40′ of arc. Refraction  30′ of arc. Annual Aberration  20″of arc. Nutation  17″ of arc. Solar Parallax   9″ of arc. StellarParallax   1″ of arc. Orbital Motion   1″ of arc. Proper Motion 0.5″ ofarc. Diurnal Aberration 0.3″ of arc. Polar Motion 0.1″ of arc.

[0153] Not all of the listed corrections need be applied, only thosecorrections larger than the required pointing accuracy of anobservation. Typically, only precession and refraction corrections needbe made.

[0154] Additional sources of systematic error come from certainmechanical errors introduced by imperfections in the telescope mount,the motor and drive train system, the servo feedback system andimprecisions in leveling the telescope. Mechanical corrections thatshould be considered when precisely aligning the telescope system arelisted in the following table. TABLE 2 Encoder Zero Offset Azimuth AxisTilt (Alt-Az Mounts) Polar Axis Misalignment (Equatorial Mounts) AxisNon-orthogonality Collimation Error Tube Flexure Mount FlexureGearing/Bearing Error Drive Train Torsion Error

[0155] These corrections are computed in a manner that can be used withany telescope of a particular mounting type, but the values of the errorparameters are unique to each individual telescope system, since theyare characteristics of that system. For example, in closed loop systems,the position feedback encoders provide a numerical value correspondingto the angular position of an axis. This numerical value is converted toa meaningful coordinate, such as RA, Dec, altitude or azimuth, byapplying a calibration algorithm to the raw encoder data. These encoderzero offset corrections are incorporated into the calibration algorithmin order to provide numerical values representing the true position ofthe telescope. The system controller compares the apparent position ofthe desired object with the position of the telescope (determined fromthe position encoder readings) and generates appropriate movementcommands to the motors in order to minimize the difference between theobject and telescope positions.

[0156] Each of the astronomical and mechanical error sources are dealtwith in precisely the same manner as initial telescope orientation. Oncethe telescope has been “aligned” the user may slew to a next object inorder to begin observation. If the next object is not precisely centeredin the telescope eyepiece, or if the next object drifts from the centerof the eyepiece during tracking, the user may manually reposition thetelescope using the position keys and commands the system to re-sync tothe object's new position. The minor corrections, thus made, form thebasis for a refinement of the Alt-Az position matrix which is thenmapped into the celestial coordinate system. As further celestialobjects are evaluated, the matrix is further refined to account forfiner and finer error sources. Although capable of such further accuracydefinition, it will be understood that the system according to theinvention is able to account for, at least, the first two majormechanical error sources during the initial orientation procedure.Certain astronomical corrections are defined by well understoodmathematical algorithms and can be easily incorporated into theorientation procedure. Thus, the pointing and tracking ability of thetelescope system according to the invention is deemed sufficientlyaccurate for deep-sky observations and astrophotography following thealignment procedures set forth in connection with FIGS. 10a, 10 b and 10c.

[0157] Since the system controller is operable to define telescopealignment and movement with respect to a polar (equatorial) mountconfiguration, it is now appropriate to discuss alignment proceduresassociated with an equatorial mount in connection with the proceduralflow charts of FIGS. 11a, 11 b and 11 c. Each of the polar alignmentprocedures first requires that the polar configuration and alignmentmode is chosen by a user during system initialization as described inconnection with the initialization procedure flow chart of FIG. 12.Needless to say, it is also necessary to that the telescope mount beconfigured as an equatorial mount and that the user properly adjusts thetelescope's declination axis such that the declination axis isperpendicular to the mount's declination plane and that the celestialpole (North or South depending upon the observer's hemisphere) falls onthe mount's declination plane.

[0158] Turning now to FIG. 11a, an “easy” polar alignment procedure isdescribed. Specifically, when the “easy” alignment procedure is selectedfrom the menu, the system prompts the user to point the telescope (usingmotion keys 112) along the RA axis until the telescope is pointed to thehorizon (RA home position). The user then depresses the enter key 113 toinform the system that the telescope tube is in its appropriate RAposition. Next, the system prompts the user to move the telescope untilthe declination setting circle reads 90°. Putting the telescope in ahome position with regard to both RA and Dec functions to zero-in theposition encoders of the declination and right ascension motors. Anysubsequent of the telescope away from its 0,0 position allows thetelescope system to directly calculate its right ascension anddeclination displacement from the 0,0 reference point.

[0159] After the previous steps are completed, the remainder of the“easy” polar alignment procedure is identical to the “easy” Alt-Azalignment procedure described in connection with FIG. 10a. Inparticular, using the time and data entries provided by the user, thetelescope system consults a data base of well known celestial objectsand selects a particular bright-object which is currently above thehorizon; the system automatically slews the telescope to the vicinity ofthat star by commanding the appropriate motion from the right ascensionand declination motors; prompts the user to center the star in the fieldof view of the telescope eyepiece and uses the observer's manualposition adjustments to refine its orientation algorithm. The process isrepeated for a next star which, when centered by the observer, allowsthe system to calculate the precise position and orientation of thetelescope with respect to the night sky (the celestial sphere).

[0160] As was the case with the Alt-Az configuration, a truncated,one-star, alignment procedure is provided to support an equatorial mountconfiguration and is depicted in the procedural flow chart of FIG. 11b.As with the previous case, a user is prompted to zero-in the motorposition encoders by commanding the telescope to move to its RA and Dechome positions. The user then selects a particular star from analphabetized stellar object data base list and may press the enter key113, causing the telescope to automatically slew to the vicinity of thatstar. The user then centers the star on the field of view of theeyepiece by depressing the position keys 112 as required. Once thechosen star is centered in the field of view of the eyepiece, the useragain presses the enter key 113 and the telescope is deemed aligned fora night of viewing.

[0161] A two-star alignment procedure is depicted in the procedural flowchart of FIG. 11c, in which the user is again prompted to move thetelescope to the RA and Dec home positions and align the telescope bysequentially selecting two stars from an alphabetized stellar objectdata base list. As each star is selected, the telescope systemautomatically slews to the vicinity of that star, following which theuser centers the star in the field of view of the eyepiece using theposition keys 112 as required, and depresses the enter key 113 in orderto inform the system that the desired star is centered.

[0162] Following definition of the home position, and following entry ofeither one or two stars in accordance with the above procedures, thetelescope system calculates the telescope's position with relation tothe night sky. Since the telescope mount comprises an equatorialconfiguration, the computation algorithm is simplified somewhat sincethe system need not convert coordinate systems, from, for example,Alt-Az to equatorial. Since an equatorial mount maneuvers in accordancewith a spherical coordinate system defined by RA and Dec, all that isrequired to orient the telescope is a simple rotation of the telescopespherical coordinate system into the celestial coordinate system. Therotation is made about the telescope's RA and Dec axes in accordancewith well established mathematical principles which need not bediscussed further herein.

[0163] Following orientation, the equatorially configured telescopesystem is now able to acquire and track selected celestial objects byappropriate motion commands to its right ascension and declination motorassemblies. Once a selected celestial object is acquired, tracking iseffected simply by commanding the right ascension motor assembly to movethe telescope about the corresponding right ascension axis at thesidereal rate in the desired direction. No further commands need begiven the declination motor assembly unless the user desires to acquirea different celestial object or, alternatively, the user desires to moreprecisely and accurately align the telescope system to compensate forsome slight originally unaccounted for error.

[0164] Returning now to FIG. 6b, the system microprocessor 121 receivesuser I/O information, as provided by the system I/O microcontroller 122and performs any needed data processing under application softwareprogram control. Data processing typically results in some form ofdesired telescope motion. The system microprocessor 122 is able tocalculate the direction and extent of any required motor motion and isfurther able to direct the appropriate motor assembly to take therequired action by passing the appropriate command through the systemI/O microcontroller 122. Motor motion commands are substantially thesame as those described in connection with the embodiment of FIGS. 5aand 5 b and are provided to the system I/O microcontroller 122 over atwo-wire serial clock and data bus 132. Certain commands are passedthrough the microcontroller 122 and are issued directly to the motor bythe system microprocessor. Such commands typically include the step ratecommands, the error count commands, the set and find LED positioncommands, and the like. Certain other information, typically read data,is held and processed by the system I/O microcontroller 122 for use bythe microprocessor when it so desires.

[0165] Notwithstanding the foregoing discussion of telescope orientationand alignment, it will be evident to one having skill in the art, thatmajor simplifications can be made to a telescope orientation andalignment procedure by incorporating additional component devices thatare able to automatically provide an indication of the orientation ofthe telescope tube with respect to the compass, i.e., north-southsensing, an automatic indication of axial tilt, i.e., telescope level,and an automatic indication of absolute position and time. Pertinent toalignment and orientation simplification is the realization thatelectronic compasses, based on magnitoresistive sensors are able toelectrically resolve a position orientation using the earth's magneticfield, to an accuracy of approximately ½ degree and with a resolution ofabout 0.1 degrees. As is well understood by those having skill in theart, the earth is surrounded by a magnetic field which has an intensityof from about 0.5 to about 0.6 gauss and includes a component parallelto the earth's surface that always points towards magnetic north. Thisfeature of the earth's magnetic field forms the basis for all magneticcompasses and it is the components of this field, parallel to theearth's surface, better used to determine compass direction.

[0166] In particular, a type of magnetic sensor, termed amagnitoresistive sensor (MR) is constructed of thin strips of a nickeliron (NiFe) magnetic film, also termed permalloy, whose electricalresistance properties vary with a change in an applied magnetic field.MR sensors have a well defined axis of sensitivity, respond to changesin an applied magnetic field as little as 0.1 milligauss, have aresponse time of less than 1 microsecond and are generally commerciallyavailable as packaged integrated circuits. MR sensors are thusparticularly suitable for use in a north-south sensing apparatus coupledto the telescope system of the exemplary embodiments.

[0167] One such configuration is shown in FIG. 17 which is asemi-schematic circuit diagram of a north-south sensor system, inaccordance with the invention, that incorporates an MR sensor,implemented as an HMC 1021S, manufactured and sold by Honeywell, Inc. ofPlymouth, Minn. The MR sensor 200 is a magnitoresistive sensing elementconstructed of NiFe thin films deposited onto a silicon substrate in amanner to define a Wheatstone resistor bridge. The MR sensor 200 furtherincorporates a current strap which is used to electrically “set” or“reset” the polarity of the device output and further allows acompensating offset field to be applied to the sensing elements tocompensate for ambient magnetic films. A supply voltage is coupled tothe MR sensor and causes a current to flow through the magnitoresistorscomprising the Wheatsone bridge configuration. A crossed applied fieldcauses magnetization in two of the oppositely placed resistors to rotatetowards the current, resulting in an increase in the correspondingresistance. In the remaining two oppositely-placed resistors,magnitization rotates away from the current resulting in a decrease inthe resistance.

[0168] Current passing through two of the arms of the Wheatstone bridgeis taken from the MR sensor at two outputs, one of which is applied tothe non-inverting input of an operational amplifier 202 configured as avoltage follower. The second output is applied to the non-invertinginput of a second operational amplifier 204, the inverting input ofwhich is coupled to receive the output of the voltage follower 202. Theoutput of the second operational amplifier 204 is directed to thenon-inverting input of a gain stage 206 which, in turn, drives an outputpin 208 to give an indication signal as to whether or not the MR sensoris aligned with the earth's magnetic field. In operation, the gain stage206 is configured so as to output a signal if the current from the MRsensor's two outputs is unbalanced, i.e., indicating that the sensor isnot aligned with the earth's magnetic field. As the center comes intoalignment with the field, current through the oppositely-placed resistorarms becomes balanced, resulting in the second operational amplifier 204having a null output. Gain stage 206, in turn, outputs a null signalindicating that the MR sensor is aligned with the earth's magneticfield, i.e., pointing towards magnetic north.

[0169] As a further indication of whether or not the MR sensor ispointing towards magnetic north, two light emitting diodes 210 and 212are coupled, in parallel fashion, to the output of the gain stage 206. Afirst light emitting diode (LED) 210 is reverse coupled to the output ofthe gain stage 206. By reverse coupled, it is meant that the negativeside of the diode is coupled to the output, while the positive side iscoupled to a reference potential, such as ground. A second diode 212 iscoupled in forward fashion to the output of the gain stage 206. Incombination, the diodes function to give an indication as to thealignment of the MR sensor with earth's magnetic field. When the sensor200 is mis-aligned in one direction, the gain stage output will beeither positive or negative, depending on whether the sensor ismis-aligned to the “left” or “right” of a centerline indicating thedirection of magnetic north. When the sensor is mis-aligned to onedirection, the gain stage output might be negative, in which case thefirst LED 210 (the negatively coupled LED) will conduct current, therebyemitting light. If the MR sensor 200 is misaligned in the oppositedirection, the gain stage 206 will output a positive signal, causing thepositively coupled LED 212 to conduct, lighting-up in turn. When thesensor is aligned to magnetic north, the gain stage output is nulled andboth LEDs are off.

[0170] It should be noted, that since these are diodes, there is aforward voltage drop associated therewith which limits their precisionin indicating magnetic north precisely. Depending on the value of theforward voltage drop of the LEDs 210 and 212, the MR sensor has a slightrange about true north during which time the gain stage 206 will notdevelop a sufficient output signal to activate either the forward orreverse biased LED. However, even within this “uncertain” range, thegain stage 206 is outputting a signal to the output pin 208 which isable to be evaluated by either an intelligent system control unit (100of FIG. 6a and 6 b) or an integrally coupled PIC processor of the typedescribed above.

[0171] It bears mentioning further that the MR sensor system is able tobe calibrated by a zero adjustment circuit 214 which is coupled to theinverting input of the second operational amplifier 204. Zero adjustmentcircuit 214 is provided in order to compensate for the input offsetscommonly exhibited by almost all operational amplifiers, and suitablycomprises an adjustable resistor coupled between positive and negativesupply voltages with a center tap defining the zero adjustmentconnection to the inverting input of the operational amplifier 204. Inoperation, the sensor is precisely aligned with the earth's magneticfield in a manufacturing jig and the variable resistor is adjusted untilsuch time as the gain stage 206 defines a null output signal. Thisindicates that the overall circuit is now balanced with circuit offsetscompensated for.

[0172] Further, the sensor circuit suitably includes a set/resetcircuit, suitably configured as a current pulse generator, which is usedto eliminate the effects of past fail hysteresis and which canelectronically set or reset the polarity of the output by applying anappropriate set or reset signal.

[0173] The MR sensor arrangement depicted in FIG. 17 has particularutility when configured on a small printed circuit board and mounted ona telescope tube in such a manner that the position axis of the centeris aligned with the long axis of the telescope. Therefore, when the MRsensor is aligned with the earth's magnetic field so as to indicatemagnetic north, the telescope tube is also positioned with its opticalaxis aligned towards magnetic north. The sensor's output 208 is coupledto the auxiliary input of the electrical interface (30 of FIGS. 3a and 3b) and is thereby made available to system processing components as anautomatic direction indication signal. In this manner, there is nolonger any need for a user to manually align the telescope to pointtowards north. Once the automated telescope system is turned on, anapplication routine automatically slews the telescope back-and-forth inthe horizontal direction and examines the “sense” of the output of thesensor. Once the automated system detects that the sensor is alignedcorrectly with north, i.e., senses a null output, the automatedtelescope system evaluates the position of the motors andinitializes-the azimuth motor assembly.

[0174] While the discussion above has concerned itself with adescription of how an MR sensor system is configured to align its selfwith the earth's magnetic field, i.e., give an indication of magneticnorth, it should be noted that the sensor can be configured to give anindication of its alignment with respect to true north. In thisparticular instance, the sensor system is aligned with true north in amanufacturing jig and the zero adjustment circuit 214 is adjusted suchthat the gain stage 206 outputs a null indication. It should beunderstood that the currents in the oppositely-disposed arms of theWheatsone bridge will necessarily be unbalanced, but the zero adjustmentcircuit 214 is adapted to compensate for this misadjustment as well ascompensate for any offsets developed by the operational amplifiers 202and 204.

[0175] It is also quite within the contemplation of the presentinvention to use an MR sensor in a 3-axis mode in order to eliminateaxial tilt concerns by electronically dealing with any axisnon-orthogonality. In this implementation, an additional MR sensor isprovided which is aligned in a plane orthogonal to the plane of thehorizontally disposed MR sensor. The additional MR sensor is configuredto measure the vertical portion of the US magnetic field, i.e., theangle of the magnetic field to the surface of the earth. Errorsintroduced by axial tilt can be quite large depending on the magnitudeof the dip, or inclination, angle.

[0176] An additional method that might be used to correct for axial tiltis to incorporate an inclinometer, or tilt sensor, with the MR sensor inorder to electrically define any mount offsets due to mount pitch. Whenan inclinometer, or tilt sensor, is incorporated with the MR sensor, thetelescope system is provided with a fully automated, electronicmethodology for 3-axis sensing. This allows the telescope system toautomatically adjust itself to a level condition as well asautomatically adjusting itself to align with either true or magneticnorth. Once these alignments are made, the axis encoders of the motorsystems are automatically initialized in order to compensate for themount alignment parameters. Therefore, electronic sensors coupled to thetelescope tube provide a very repeatable position index when inproximity with the mount's axis crossings. Electronic sensors are usedas fixed point high-resolution devices, with fine positioning beingprovided by the motor encoders. Since pointing accuracy typicallydepends on the flexure characteristics of a tube, the mechanicalstability of the tube and mount combination and the quality of thegearing between the drive motor and a telescope mount, it will beunderstood that pointing accuracy can be simply and easily added to ainexpensive telescope system that might exhibit a certain mechanicallooseness.

[0177] As was developed above, in order to completely align a telescopesystem, the user or an intelligent telescope system need only know thedirection of north, the inclination of the horizon (level), the time anddate and its position on the earth's surface. If these quantities areknown, there is no further information that need be provided to anytelescope system to allow it to thereafter point to any designatedobject with a known ephemeris, other than an command to do so. Time anddate information are accessible by receiving a broadcast signal, WWV,which is made available for such purpose. The automated telescope systemaccording to the invention fully contemplates being able to couple asource of WWV information into the intelligent system control unit sothat the control unit is able to continually update date and timeinformation such that the time and date variables of the alignmentsystem are eliminated. WWV is in Fort Collins, Colorado and broadcastscontinuous time and frequency signals on 2.5, 5, 10, 15 and 20 MHz. Allfrequencies provide the same information, with frequencies above 10 MHzworking best during daylight hours, while lower frequencies working bestat night. The beginning of each hour is identified by a 0.8 second long1500 Hz tone, with the beginning of each minute identified by a similarlength 1000 Hz tone. Second pulses are given by a 440 Hz tone the 29thand 59th second pulses of each minute being omitted. Time signals may beinput directly from a WWV receiver, with the various frequency tonesdefining clock signals which can be processed by the intelligent systemcontrol unit to update its date and time information.

[0178] Alternatively, WWV information may be received via an Internetconnection by a laptop-type personal computer system. Informationprocessed by the laptop can be transferred to the intelligent systemcontrol unit over the auxiliary input bus of the interface panel in amanner as described above.

[0179] Accurate location information can be provided to the intelligentsystem control unit by use of a global positioning system (GPS) ordifferential global positioning system (DGPS) receiver configured withan NMEA interface. The NMEA interface is a well recognized interfaceprotocol which can additionally be coupled to the auxiliary interface toproved a source of location information directly to the intelligentsystem control unit. Once the intelligent system control unit haslocation, time and date information available as well as the output ofthe “north” and “level” sensors, the intelligent system control unitbecomes fully aware not only of its location but also of the spatialorientation of the telescope system to which it is coupled.

[0180] The systems and methods associated with 3-axis sensing, asdescribed above, are equally applicable to additional “pointing” or“acquisition” devices beyond the novel telescope system in accordancewith the invention. Indeed, 3-axis sensing systems are adaptable to bemounted on a detachable viewfinder or telescope eyepiece such that auser need only direct the eyepiece in accordance with the signalsreceived from the sensing devices in order to orient themselves withboth horizon and with north. Binoculars and heads-up-display (HUD)goggles are also able to be configured with 3-axis sensing devices inthe above manner in order to provide them with an orientationcapability.

[0181] A further feature of the intelligent system control unit (100 ofFIGS. 6a and 6 b) is the construction of the light source for providinguniform illumination to the LCD display screen 102. With reference, now,to FIG. 13, a cusped, curvilinear optical light box 150 is disposed onthe surface of the control unit's electronic component circuit board,and positioned in the region just beneath the LCD display screen, andhaving approximately the same footprint. The light box defines agenerally rectangular, hollow enclosure, with its surface describing apair of curvilinear arcs 151 and 152, laterally symmetrical about acentral, downward projecting, cusp which bisects the surface.Illumination LEDs 153, 154, 155 and 156 are arranged, in pairs, alongeach of the short sides of the light box and are configured to shineinto the enclosure, in the direction of the cusp.

[0182] Each of the curvilinear surfaces are rendered translucent, bypainting them white, for example, or by constructing the reflector froma translucent material such as a suitable plastic. The translucentproperty of the surface allows the light developed by the LEDs to shinethrough the surface, but permits each arcuate portion to diffuse thelight and direct it (as a backlight source) onto the LCD display in adiffusion pattern promoting uniform illumination.

[0183] In a conventional, flat-surfaced light box, light energy, from anon-coherent, uniform, source such as an LED, is scattered through thetranslucent surface only when the scattering vector of the light makes arelatively large angle with the surface in question. As the surfaceelement is farther and farther away from the light source, thescattering angle becomes correspondingly smaller, until the light isscattered along the surface underside (perpendicular scatter vector) andvery little is scattered through the material and onto the display(Normal scatter vector). This phenomenon results in a dark, orrelatively unilluminated, region in the center of the display, while theedges are over illuminated (so called hot spots). This makes the displayhard to read, particularly at night.

[0184] The curvilinear arcuate surfaces of the light box 150 accordingto the invention, are shaped to insure a substantially greater degree ofnormal scattering out of the light box at the light path extremities,i.e., the portion of the surface farthest from the light source (thecenter). Moreover, the gradual curvature of each surface maintains thesurface at a relatively constant scattering angle with respect to thelight source. Thus the light energy diffused through the surface isrelatively constant along the surface in the direction from the lightsource towards the cusp. In the region of the cusp itself, surfacereflection adds an additional component of illumination to the lightdirected onto the display. Light scattered from a first arcuate surface151 at a low angle, is reflected from the second arcuate surface 152 atan equal angle and thus towards the display. Low angle surfacescattering is therefore recovered to some degree and forms an additionalcomponent of illumination in the central region.

[0185] It should be evident, from the foregoing discussion, that thevarious components and elements of the present invention are not limitedto the particular telescope systems illustrated thus far. Indeed, thetelescope and motor systems described in connection with the illustratedembodiments, were chosen because the novel components of the inventionappeared externally and admitted of more direct identification. Turningnow to FIG. 14, there is depicted a further embodiment of a fullyautomated telescope system, in which the motor assemblies are notconfigured as add-on components, but rather are integrated into thetelescope system.

[0186] The telescope system of FIG. 14 is shown as configured to operatein equatorial mode, with its legs 160 a, 160 b and 160 c positioned toequatorially align the telescope such that the top surface 161 of thebase housing 162 rotates to define the system's RA plane. Right and leftfork arms 163 and 164, respectively, support the telescope tube 165 andprovide its declination rotation axis. The base housing 162 additionallysupports an interface panel substantially similar to the interface panel30 of FIGS. 1, 2, 3 a and 3 b, but without the serial interfaceconnections to the Alt (Dec) and Az (RA) motor assemblies. Rather, theinterface panel 166 provides for plug-in connection of either of thepreviously described control units, and for plug-in connection of amultiplicity of auxiliary devices through an auxiliary bus.

[0187] Motor assembly coupling connections are not required for theembodiment illustrated in FIG. 14, since the motor assemblies areincorporated into the telescope structure. Thus, external connectionsare not required. However, electrical connection to the motor assembliesis made via an identical 2-wire serial interface as with previousembodiments, except that the motor interface busses are internalizedinto the telescope structure as well.

[0188] A first, declination (or altitude) motor assembly is configuredinto a motor enclosure 168, formed by in the hollow interior of one ofthe fork arms; the right fork arm 163 in the illustrated embodiment.FIG. 15 depicts the internal configuration of the fork arm 163 andillustrates the position of a declination (Alt) motor assembly 170 andits associated gear train 172 within the fork arm.

[0189] A second, right ascension (or azimuth) motor assembly isconfigured to fit within the base housing 162 of the telescope system,in a manner depicted in FIG. 16. The RA (Az) motor assembly 174 and itsassociated gear train 176 are disposed in a hollow enclosure formed justbeneath the RA surface 161 of the telescope. Direct DATA, CLK, power andground couplings are taken from hardwired connections made between thecontrol unit input of the interface panel 166 and each respective motorassembly. Each motor assembly 170 and 174 comprises the same electroniccomponents as those described in connection with previous embodimentsand are, therefore, endowed with the same degree of intelligence.

[0190] The telescope system embodiment of FIGS. 14, 15 and 16 may becontrolled by either the semi-intelligent or fully intelligent controlunits described previously, with the same degree of functionalperformance. Moreover, the auxiliary bus supports the same numbers andtypes of auxiliary devices.

[0191] It should be understood, therefore, that distributingintelligence across various functional components of a telescope system,is not limited to the particular configuration of the telescope. Certainportions of the system may be integrated into the telescope in theinterest of compactness and design efficiency without sacrificing any ofthe virtues of intelligence distribution. All that these integratedsystems lack is the ability to be lobotomized to a purely mechanicalsystem operated entirely by manual manipulation.

1. An automated telescope system comprising: a telescope configured forrotation about two orthogonal axes; a signal bus, configured to passdata and control signals between and among peripheral devices connectedthereto; a central control processor coupled to the signal bus, thecontrol processor communicating data and control signals between andamong peripheral devices coupled to the signal bus; first and secondmotor assemblies, each motor assembly including: an electric motorcoupled to move the telescope about one of the two orthogonal axes; acontrol circuit coupled to the motor and to the signal bus, the controlcircuit developing control signals for commanding motor movement; and aposition indication circuit coupled to a respective axis and to thecontrol circuit, the position indication circuit providing positionindication signals to the respective control circuit; wherein, thecontrol circuit commands motor movement and evaluates motor positionindication signals in operative response to control signals receivedfrom the central control processor.
 2. The automated telescope systemaccording to claim 1, wherein the central control processor performshigh level application software execution tasks and numerical processingin order to define appropriate motor motion commands, the centralcontrol processor providing said motor motion commands to each controlcircuit over said signal bus, each control circuit developing controlsignals for commanding motor movement in operative response thereto. 3.The automated telescope system according to claim 2, wherein eachcontrol circuit includes means for acquiring, storing and recallingmotor position information for its respective motor.
 4. The automatedtelescope system according to claim 3, wherein the position indicationcircuit comprises an optical encoder, coupled to its respective motorshaft, the optical encoder developing electronic pulses, each pulseindicating a finite arcuate movement of the encoder, thereby indicatinga finite arcuate movement of its respective motor.
 5. The automatedtelescope system according to claim 4, wherein the signal bus is aserial bus, the central control processor communicating with eachcontrol circuit over a respective 2-wire serial connection in accordancewith a packet communication protocol.
 6. An automated telescope systemof the type including a telescope mounted for rotation about twosubstantially orthogonal axes, the automated telescope systemcomprising: first and second motor assemblies, each coupled to rotatethe telescope about a respective one of the axes, each motor assemblyincluding: a motor having a rotatable shaft; an optical encoder coupledto the motor shaft for providing motor movement feedback information;and a motor control processor for commanding motor movement andevaluating optical encoder feedback information; and a command unitconnected to each motor assembly over a respective serial communicationbus, the command unit receiving telescope movement commands from a userand developing appropriate control signals for communication to themotor control processor.
 7. The automated telescope system according toclaim 6, the command unit further comprising: a housing configured to becomfortably hand held; a keypad, disposed on the housing formanipulation by a user to define telescope movement commands; and amicrocontroller, disposed within the housing, the microcontrollertranslating user manipulation of the keypad into control signals, thecontrol signals directed to each motor assembly over the serialcommunication bus.
 8. The automated telescope system according to claim7, the command unit further comprising: a memory; and a microprocessor,wherein the memory is adapted to host application software program code,executable by the microprocessor, the microprocessor performing highlevel application software execution tasks and numerical processing inorder to define commands to the microcontroller, the microcontrollertranslating said commands into control signals for each motor assembly.9. The automated telescope system according to claim 8, furthercomprising: a first database, contained in memory, the first databaseincluding a catalog of celestial objects, each identified by a set ofcelestial coordinates; and a second database, contained in memory, thesecond database including a catalog of geographical locations, eachidentified by a set of earth-based coordinates.
 10. The automatedtelescope system according to claim 9, a user identifying a geographicallocation from the second database, proximate to the user's actuallocation, wherein the command unit includes program means fortranslating earth-based coordinates into celestial coordinates.
 11. Theautomated telescope system according to claim 10, wherein the commandunit includes means for receiving telescope position indications fromeach motor assembly, the command unit processing the positionindications in combination with the geographical location in order todefine the telescope's orientation with respect to the celestialcoordinate system.
 12. The automated telescope system according to claim11, wherein the command unit includes means for automatically traversingthe telescope to a desired celestial object and for tracking thecelestial path of said celestial object without further intervention bya user.
 13. The automated telescope system according to claim 12,wherein the telescope is provided in an alt-azimuth configuration. 14.The automated telescope system according to claim 13, wherein thetelescope is provided in a polar configuration.
 15. The automatedtelescope system according to claim 7, the housing including an LCDdisplay screen, the display screen illuminated by a light sourceproviding uniform illumination to the screen, the light sourcecomprising: a cusped, curvilinear light box positioned within thehousing and beneath the display screen, the cusp bisecting the light boxand disposed substantially midway between opposing ends of the lightbox; and a plurality of light sources configured to shine into the lightbox in the direction of the cusp, wherein each arcuate portion of thecusp diffuses light and directs it onto the display screen at asubstantially constant scattering angle with respect to the lightsources.
 16. The automated telescope system according to claim 15,wherein the light sources are light-emitting-diodes.
 17. The automatedtelescope system according to claim 16, wherein the light box isconstructed of a translucent material.
 18. The automated telescopesystem according to claim 6, the serial communication bus furthercomprising: an interface panel; a pair of motor control buses, eachcoupled between the interface panel and a respective motor assembly; acommand unit bus, coupled between the interface panel and the commandunit; and an auxiliary bus, coupled to the interface panel andconfigured to promote data and control signal communication between thecommand unit and a plurality of peripheral devices serially coupled tothe auxiliary bus.
 19. The automated telescope system according to claim18, wherein peripheral devices coupled to the serial bus are selectedfrom a group consisting of a global positioning system device, a timekeeping device, an electronic compass, an MR sensor, a personal computerand an additional command unit.
 20. A fully automated telescope systemwith functional intelligence distributed between independent components,the telescope system of the type including a telescope mounted forrotation about two substantially orthogonal axes, the automatedtelescope system comprising: an intelligent motor module, the motormodule including means for commanding a motor to rotate the telescope adesired arcuate amount about a respective axis, and further includingmeans for determining the actual arcuate amount of rotation; a commandmodule, including means for translating a user input into signalssuitable for transmission to the motor module, the motor moduleprocessing said signals into motor motion commands; and a communicationbus coupled between the command module and the motor module.
 21. Thefully automated telescope system according to claim 20, furthercomprising: first means for determining a horizontal aspect of thetelescope; second means for determining a vertical aspect of thetelescope; and wherein the first and second means provide signalscorresponding to each determined aspect to the command module.
 22. Thefully automated telescope system according to claim 21 furthercomprising: means for defining a geographical position of the telescope;and means for processing the geographical position, the horizontalaspect and the vertical aspect of the telescope in order to orient thetelescope with respect to a celestial coordinate system.
 23. The fullyautomated telescope system according to claim 22, further comprisingmeans for selecting a desired celestial object, wherein the telescopesystem automatically traverses to that object without furtherintervention by a user.
 24. The fully automated telescope systemaccording to claim 22, further comprising means for automaticallyinputting a time parameter.
 25. The fully automated telescope systemaccording to claim 21, wherein the first means comprises an MR sensor,configured to provide an indication signal when the telescope ispointing in a particular direction relative to a predefined compasspoint.
 26. The fully automated telescope system according to claim 25,wherein the MR sensor is coupled to the communication bus, the MR sensorproviding indication signals to the command module, the command moduletranslating said indication signals into motor control signals suitablefor transmission to the motor module, the motor module processing saidmotor control signals into motor motion commands, such that thetelescope is automatically positioned in the particular directionrelative to the predefined compass point in operative response to theindication signals.
 27. In a computerized telescope system of the typeincluding a telescope coupled for rotation about two orthogonal axes, amethod for orienting the telescope system with respect to a sphericalcoordinate system, the method comprising: providing a pair of motors,each coupled to rotate the telescope about a respective one of theorthogonal axes, each motor including a positional reference indicator,each positional reference indicator defining an arcuate position of thetelescope with respect to its respective axis; providing a controlprocessor, the processor connected to receive positional referenceinformation from each positional reference indicator; inputting a timeindicia to the control processor; inputting a date indicia to thecontrol processor; moving the telescope about a first one of the axes toa first reference position; recording positional reference data from therespective positional reference indicator as a first positional index;moving the telescope about the second of the axes to a second referenceposition; recording positional reference data from the respectivepositional reference indicator as a second positional index; andprocessing the first and second positional indices and the time and dateindicia so as to define a virtual coordinate location of the telescopesystem with respect to the spherical coordinate system.
 28. The methodaccording to claim 27, further comprising: identifying, to the controlprocessor, a spherical coordinate of a desired viewing object, thecontrol processor calculating a set of respective positional referenceindicia for each motor such that when the respective positionalreference indicators are at said indicia, the telescope is pointingsubstantially at said desired viewing object; and commanding thetelescope system to actuate the motors so as to point the telescope atthe desired object.
 29. The method according to claim 28, furthercomprising: reading a first set of positional reference data from therespective positional reference indicators when the telescope ispointing at the desired viewing object; evaluating the position of thedesired viewing object in a viewing field of the telescope; actuatingthe motors so as to position the desired viewing object in a centralregion of the viewing field; recording a second set of positionalreference data from the respective positional reference indicators whenthe desired viewing object is positioned in the central region of theviewing field; and processing the first and second sets of positionalreference data so as to refine the virtual coordinate location of thetelescope system with respect to the spherical coordinate system. 30.The method according to claim 29, wherein the spherical coordinatesystem is the celestial coordinate system.
 31. The method according toclaim 30, wherein the orthogonal telescope axes define an alt-azimuthmount configuration.
 32. The method according to claim 31, wherein theposition reference indicators comprise encoders coupled to theirrespective axes, each encoder defining an arcuate displacement of thetelescope about its respective axis, the arcuate displacement based onthe respective first or second positional index.
 33. The methodaccording to claim 32, wherein the first reference position is adeterminable angle with respect to North, and wherein the secondreference position is a determinable angle with respect to horizontal.34. The method according to claim 33, wherein the first referenceposition is substantially North, and wherein the second referenceposition is substantially horizontal.
 35. In a computerized telescopesystem of the type including a telescope coupled for rotation about twoorthogonal axes, the orthogonal axes defining a first coordinate system,a method for orienting the telescope system with respect to a sphericalcoordinate system, the method comprising: providing first and secondmotors, each motor coupled to rotate the telescope about a respectiveone of the orthogonal axes; providing first and second arcuate positionindicators, each position indicator coupled to a respective one of thefirst and second motors, each position indicator indicating an arcuateposition of the telescope with respect to its respective axis in thefirst coordinate system; providing a control processor, the processorcoupled to receive arcuate positions from the arcuate positionindicators; moving the telescope about a first one of the axes to afirst reference position; recording a first arcuate positioncorresponding to said first reference position of said first axis;moving the telescope about a second one of the axes to a secondreference position; recording a second arcuate position corresponding tosaid second reference position of said second axis; processing the firstand second recorded arcuate positions so as to translate the telescopeposition in the first coordinate system to a virtual telescope positionin the spherical coordinate system; and inputting a rotation metric, therotation metric rotating the virtual telescope position in the sphericalcoordinate system in accord with a major axis of the sphericalcoordinate system.
 36. The method according to claim 35, furthercomprising: identifying the first and second recorded arcuate positionsas respective first and second reference positions, one for each axis;identifying, to the control processor, a spherical coordinate of adesired viewing object, the control processor translating said sphericalcoordinate into a set of desired arcuate positions with respect to thefirst and second reference positions, such that when each respectiveposition indicator is at the respective desired arcuate position, thetelescope is pointing substantially at said desired viewing object; andcommanding the telescope system to actuate the motors so as to point thetelescope at the desired object.
 37. The method according to claim 36,further comprising: reading a first set of arcuate positions from therespective positional reference indicators when the telescope ispointing at the desired viewing object; evaluating the position of thedesired viewing object in a viewing field of the telescope; actuatingthe motors so as to position the desired viewing object in a centralregion of the viewing field; reading a second set of arcuate positionsfrom the respective positional reference indicators when the desiredviewing object is positioned in the central region of the viewing field;and processing the first and second sets of arcuate positions so as torefine the virtual coordinate location of the telescope system withrespect to the spherical coordinate system.
 38. The method according toclaim 37, wherein the first coordinate system is a rectangularcoordinate system, the orthogonal telescope axes defining an alt-azimuthmount configuration, and wherein the spherical coordinate system is acelestial coordinate system, a celestial coordinate defined by a rightascension and a declination.
 39. The method according to claim 38,wherein the rotation metric aligns a virtual right ascension of thetelescope with a right ascension of the celestial coordinate system. 40.The method according to claim 39, wherein the rotation metriccorresponds to time.
 41. The method according to claim 38, wherein theposition reference indicators comprise encoders coupled to theirrespective axes, each encoder defining an arcuate displacement of thetelescope about its respective axis.
 42. The method according to claim41, wherein the first reference position is a determinable angle withrespect to North, and wherein the second reference position is adeterminable angle with respect to horizontal.
 43. The method accordingto claim 42, wherein the first reference position is substantiallyNorth, and wherein the second reference position is substantiallyhorizontal.
 44. In an automated alt-azimuth telescope system whereorthogonal altitude and azimuth axes define a first earth-basedcoordinate system, a method for orienting the telescope system withrespect to a celestial coordinate system comprising: providing altitudeand azimuth motors, each motor coupled to rotate the telescope about itsrespective axis; providing altitude and azimuth axial rotationindicators, each coupled to its respective axis and each outputting arotational datum indicating an amount of telescope rotation about therespective axis; providing a control processor; inputting a geographicalindicia into the control processor; rotating the telescope about theazimuth axis to an azimuth reference index; reading and recording theazimuth rotational datum corresponding to the azimuth reference indexoutput by the azimuth axial rotation indicator; rotating the telescopeabout the altitude axis to an altitude reference index; reading andrecording the altitude rotational datum corresponding to the altitudereference output by the azimuth axial rotation indicator; and processingthe geographical indicia and the azimuth and altitude rotational data totranslate between the earth-based coordinate system into the celestialcoordinate system.
 45. The method according to claim 44, furthercomprising: identifying, to the control processor, a celestialcoordinate of a first desired viewing object, the control processortranslating said celestial coordinate into a set of desired rotationaldata with respect to the azimuth and altitude reference positions, suchthat when each respective axial rotation indicator outputs the desiredrotational datum, the telescope is pointing substantially at saiddesired viewing object; and commanding the telescope system to actuatethe motors so as to point the telescope at the desired object.
 46. Themethod according to claim 45, further comprising: evaluating theposition of the first desired viewing object in a viewing field of thetelescope; actuating the motors to reposition the desired viewing objectin a central region of the viewing field; and updating the altitude andazimuth rotational data so as to refine the translation between theearth-based and the celestial coordinate systems.
 47. The methodaccording to claim 46, further comprising: identifying, to the controlprocessor, a celestial coordinate of a second desired viewing object,the control processor translating said celestial coordinate into a setof desired rotational data with respect to the azimuth and altitudereference positions, such that when each respective axial rotationindicator outputs the desired rotational datum, the telescope ispointing substantially at said second desired viewing object; andcommanding the telescope system to actuate the motors so as to point thetelescope at the second desired object.
 48. The method according toclaim 47, wherein the evaluating and updating steps are repeated for thesecond desired viewing object, so as to further refine the translationbetween the earth-based and the celestial coordinate systems.
 49. Anautomated telescope system including: a telescope tube having a majorlongitudinal axis; and an MR sensor disposed along the major axis of thetelescope tube, the MR sensor configured to provide an indication signalwhen the telescope is pointing in a particular direction relative to apredefined compass point.
 50. The fully automated telescope systemaccording to claim 49, wherein the MR sensor is coupled to acommunication bus, the MR sensor providing indication signals to acommand module, the command module translating said indication signalsinto motor control signals suitable for transmission to a motor module,the motor module processing said motor control signals into motor motioncommands, such that the telescope is automatically positioned in theparticular direction relative to the predefined compass point inoperative response to the indication signals.
 51. An illumination sourcefor providing uniform illumination to an LCD display screen, theillumination source comprising: a cusped, curvilinear light boxpositioned beneath the display screen, the cusp bisecting the light boxand disposed substantially midway between opposing ends of the lightbox; and a plurality of light sources configured to shine into the lightbox in the direction -of the cusp, wherein each arcuate portion of thecusp diffuses light and directs it onto the display screen at asubstantially constant scattering angle with respect to the lightsources.
 52. The illumination source according to claim 51, wherein thelight sources are light-emitting-diodes.
 53. The illumination sourceaccording to claim 52, wherein the light box is constructed of atranslucent material.